Is There a Time-Dependent Contamination Risk to Open Surgical Trays During Total Hip and Knee Arthroplasty?

Background: Periprosthetic joint infection (PJI) after total hip and knee arthroplasty (TJA) is a devastating complication and intraoperative contamination can be a source for PJI. Currently, many measures are performed intraoperatively to reduce the risk of contamination. The primary purpose of this study was to determine if there is a time-dependent risk of contamination to open sterile surgical trays during TJA cases. Methods: A prospective intraoperative culture swab study was performed. Standard sterile operating room trays without instruments were utilized as the experimental trays. These were opened simultaneously with all other surgical instrumentation needed for the procedure. These trays were left on an isolated Mayo stand next to the scrub tech's table and swabbed at 30-minute intervals. The first swab was performed immediately after opening all sets and the last swab performed on closure of the incision. A new section of the grid-lined tray was swabbed for each data point and the culture analysis was conducted by our institutions' microbiology lab for both quantitative and qualitative analysis. Operating suite room temperature and humidity data was also gathered. Results: Twenty-three consecutive primary TJA cases in high air turnover rooms were included. 13 of the 23 (57%) cases demonstrated culture positive bacterial growth on at least one time point. Of the 109 independent swabs collected, 19 (17%) had bacterial growth. The most common bacterial species isolated was Staphylococcus epidermidis. There were no statistically significant associations between time (p= 0.35), operating room (OR) temperature (p = 0.99), and OR humidity (p = 0.07) and with bacterial growth. Conclusion: In spite of isolating an organism in 57% of cases, we could not identify a time-dependent increase in bacterial contamination throughout our operative cases. We were unable to associate OR environmental temperature and humidity to bacterial growth. Level of Evidence: II.

Two-Stage Exchange Arthroplasty for Periprosthetic Joint Infection Following Total Hip or Knee Arthroplasty Is Associated With High Attrition Rate and Mortality.

BACKGROUND: We sought to determine the ultimate fate of patients undergoing resection arthroplasty as a first stage in the process of 2-stage exchange and evaluate risk factors for modes of failure. METHODS: A retrospective case study was performed including all patients with minimum 2-year follow-up who underwent first-stage resection of a hip or knee periprosthetic joint infection from 2008 to 2015. Patient demographics, laboratory, and health status variables were collected. The primary outcome analyzed was defined as failure to achieve an infection-free 2-stage revision. Univariate pairwise comparison followed by multivariate regression analysis was used to determine risk factors for failure outcomes. RESULTS: Eighty-nine patients underwent resection arthroplasty in a planned 2-stage exchange protocol (27 hips, 62 knees). Mean age was 64 years (range, 43-84), 56.2% were males, and mean follow-up was 56.3 months. Also, 68.5% (61/89) of patients underwent second-stage revision. Of the 61 patients who complete a 2-stage protocol, 14.8% (9/61) of patients failed with diagnosis of repeat or recurrent infection. Mortality rate was 23.6%. Multivariate analysis identified risk factors for failure to achieve an infection-free 2-stage revision as polymicrobial infection (P < .004; adjusted odds ratio [AOR], 7.8; 95% confidence interval [CI], 2.1-29.0), McPherson extremity grade 3 (P < .024; AOR, 4.1; 95% CI, 1.2-14.3), and history of prior resection (P < .013; AOR, 4.7; 95% CI, 1.4-16.4). CONCLUSION: Patients undergoing resection arthroplasty for periprosthetic joint infection are at high risk of death (24%) and failure to complete the 2-stage protocol (32%). Those who complete the 2-stage protocol have a 15% rate of reinfection at 4.5-year follow-up.

Association of Preoperative Opioid Use and Prolonged Postoperative Opioid Use Following Total Ankle Arthroplasty.

BACKGROUND: Perioperative opioid consumption has received a great deal of recent attention. However, perioperative opioid utilization in the total ankle arthroplasty (TAA) population has not been well studied. We sought to identify factors associated with postoperative opioid use following TAA. METHODS: The PearlDiver Research Program was used to query the Humana, Inc, administrative claims database from 2007 to 2017 for patients undergoing TAA. Additional variables of interest were identified using ICD-9 and ICD-10 codes. Preoperative opioid use was defined as having filled an opioid prescription in the 3 months before TAA. Prescription opioid claims data were tracked for 12 months postoperatively. Risk ratios (RRs) were calculated and multivariate analysis was performed at 3, 6, and 12 months postoperatively. RESULTS: A total of 544 patients who underwent TAA were identified, with 180 (33.1%) filling an opioid prescription preoperatively. Those filling prescriptions preoperatively had a significantly greater risk for postoperative opioid use compared to those not taking opioids (RR: 4.36 [95% confidence interval (CI): 2.80-6.80] at 12 months). Anxiety or depression (RR: 2.27 [1.44-3.59]), low back pain (LBP) (RR: 2.27 [1.50-3.42]), and fibromyalgia (RR: 2.15 [1.42-3.28]) were also found to increase the risk of taking opioids at 12 months postoperatively. Multivariate analysis found preoperative opioid use to be the strongest predictor of postoperative opioid use. CONCLUSIONS: Nearly one-third of patients filled an opioid prescription within 3 months of TAA, and filling a prescription preoperatively was the strongest factor associated with postoperative opioid use. Fibromyalgia, depression or anxiety, and LBP were also associated with an increased likelihood of postoperative opioid use. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

What Are the Costs of Cervical Radiculopathy Prior to Surgical Treatment?

STUDY DESIGN: Retrospective, observational study. OBJECTIVE: To examine the costs associated with nonoperative management (diagnosis and treatment) of cervical radiculopathy in the year prior to anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: While the costs of operative treatment have been previously described, less is known about nonoperative management costs of cervical radiculopathy leading up to surgery. METHODS: The Humana claims dataset (2007-2015) was queried to identify adult patients with cervical radiculopathy that underwent ACDF. Outcome endpoint was assessment of cumulative and per-capita costs for nonoperative diagnostic (x-rays, computed tomographic [CT], magnetic resonance imaging [MRI], electromyogram/nerve conduction studies [EMG/NCS]) and treatment modalities (injections, physical therapy [PT], braces, medications, chiropractic services) in the year preceding surgical intervention. RESULTS: Overall 12,514 patients (52% female) with cervical radiculopathy underwent ACDF. Cumulative costs and per-capita costs for nonoperative management, during the year prior to ACDF was $14.3 million and $1143, respectively. All patients underwent at least one diagnostic test (MRI: 86.7%; x-ray: 57.5%; CT: 35.2%) while 73.3% patients received a nonoperative treatment. Diagnostic testing comprised of over 62% of total nonoperative costs ($8.9 million) with MRI constituting the highest total relative spend ($5.3 million; per-capita: $489) followed by CT ($2.6 million; per-capita: $606), x-rays ($0.54 million; per-capita: $76), and EMG/NCS ($0.39 million; per-capita: $467). Conservative treatments comprised of 37.7% of the total nonoperative costs ($5.4 million) with injections costs constituting the highest relative spend ($3.01 million; per-capita: $988) followed by PT ($1.13 million; per-capita: $510) and medications (narcotics: $0.51 million, per-capita $101; gabapentin: $0.21 million, per-capita $93; NSAIDs: 0.107 million, per-capita $47), bracing ($0.25 million; per-capita: $193), and chiropractic services ($0.137 million; per-capita: $193). CONCLUSION: The study quantifies the cumulative and per-capital costs incurred 1-year prior to ACDF in patients with cervical radiculopathy for nonoperative diagnostic and treatment modalities. Approximately two-thirds of the costs associated with cervical radiculopathy are from diagnostic modalities. As institutions begin entering into bundled payments for cervical spine disease, understanding condition specific costs is a critical first step. LEVEL OF EVIDENCE: 3.

Outcomes of Surgical Management of Borderline Hip Dysplasia: A Systematic Review.

Background: Multiple reports have detailed clinical outcomes in surgically treated patients with borderline hip dysplasia. The purpose of this systematic review was to define patient outcomes following these surgical interventions. Methods: Searches were developed using an iterative process of gathering and evaluating terms. Comprehensive strategies including both index and keyword methods were devised for the following databases: PubMed, Embase, and Cochrane CENTRAL. Independent review and data abstraction was performed by two authors. Inclusion criteria were clear delineation of outcomes for patients with borderline hip dysplasia (Lateral center edge angle (LCEA) 18-25°) and outcomes following hip arthroscopy and/ or periacetabular osteotomy (PAO), including patient reported outcomes (PROs), revision arthroscopy, and conversion to Total Hip Arthroplasty. Exclusion criteria included alternative surgical procedures including "shelf" or "salvage" osteotomies, studies without patient outcomes or clearly delineated results for patients with borderline dysplasia, inclusion of <5 borderline patients, or inadequate follow-up defined as < 12 months. Results: Thirteen of 2109 articles met inclusion criteria for full data analysis. 505 patients (mean age 29.6 years, 67.7% female) with borderline dysplasia (mean LCEA 22.3°) were treated with hip arthroscopy. The majority of studies reported outcomes using the modified Harris Hip Score (mHHS) and Hip Outcome Score Sports Specific Subscale (HOS-SSS); all showed post-operative improvement with mean increase of 21.0 and 26.8 points, respectively. Revision arthroscopy rate was 7.5% (31/412), and a total hip arthroplasty conversion rate was 4.0% (18/455). The average combined total reoperation rate was 13.7% (69/505). Conclusion: Arthroscopic management of borderline hip dysplasia is associated with meaningful improvement in PRO scores. However, there appears to be a high reoperation rate including both arthroscopic and open revision procedures. There is a paucity of studies reporting outcomes of PAO in patients with borderline hip dysplasia.Level of evidence: Systematic review of Level III and Level IV studies.

Strain in Posterior Instrumentation Resulted by Different Combinations of Posterior and Anterior Devices for Long Spine Fusion Constructs.

STUDY DESIGN: Clinically related experimental study. OBJECTIVE: Evaluation of strain in posterior low lumbar and spinopelvic instrumentation for multilevel fusion resulting from the impact of such mechanical factors as physiologic motion, different combinations of posterior and anterior instrumentation, and different techniques of interbody device implantation. SUMMARY OF BACKGROUND DATA: Currently different combinations of posterior and anterior instrumentation as well as surgical techniques are used for multilevel lumbar fusion. Their impact on risk of device failure has not been well studied. Strain is a well-known predictor of metal fatigue and breakage measurable in experimental conditions. METHODS: Twelve human lumbar spine cadaveric specimens were tested. Following surgical methods of lumbar pedicle screw fixation (L2-S1) with and without spinopelvic fixation by iliac bolt (SFIB) were experimentally modeled: posterior (PLF); transforaminal (TLIF); and a combination of posterior and anterior interbody instrumentation (ALIF+PLF) with and without anterior supplemental fixation by anterior plate or diverging screws through an integrated plate. Strain was defined at the S1 screws, L5-S1 segment of posterior rods, and iliac bolt connectors; measurement was performed during flexion, extension, and axial rotation in physiological range of motion and applied force. RESULTS: The highest strain was observed in the S1 screws and iliac bolt connectors specifically during rotation. The S1 screw strain was lower in ALIF+PLF during sagittal motion but not rotation. Supplemental anterior fixation in ALIF+PLF diminished the S1 strain during extension. Strain in the posterior rods was higher after TLIF and PLF and was increased by SFIB; this strain was lowest after ALIF+PLF, as supplemental anterior fixation diminished the strain during extension, in particular, cages with anterior screws more than anterior plate. Strain in the iliac bolt connectors was mainly determined by direction of motion. CONCLUSIONS: Different devices modify strain in low posterior instrumentation, which is higher after transforaminal and posterior techniques, specifically with spinopelvic fixation. LEVEL OF EVIDENCE: N/A.

An analysis of spine fusion outcomes in sheep pre-clinical models.

PURPOSE: The ovine model is often used to evaluate new spine fusion technologies prior to clinical testing. An important aspect of designing sheep surgery protocols is to select the appropriate postoperative time period for comparing fusion outcomes. Unfortunately, determining the ideal study endpoint is complicated by the fact that prior published studies have not used consistent timeframes. Thus, the primary aim of this study was to provide a reference for investigators as to the expected fusion outcomes of control groups at varying timepoints in sheep spine surgery models. METHODS: We identified published sheep fusion studies using autograft, interbody cages, and/or instrumentation. Fusion data were extracted, converted to a common scale, and analyzed across studied timepoints. RESULTS: Overall, 29 studies of 360 fusion levels were identified: 11 ALIF (158 levels), 3 PLIF/TLIF (28 levels), 8 PLF (90 levels), and 7 ACDF (84 levels). Studied timepoints ranged from 4 to 48 weeks postoperative. In general, fusion rates varied across techniques and instrumentation. The time to reach solid fusion differed by as many as 20 weeks between control groups. CONCLUSIONS: Recommended timeframes for future studies designed to show either superiority over controls or equivalent outcomes with controls were developed based on aggregate results. Designating ideal study endpoints for sheep fusion models has both ethical implications associated with responsible use of animals in research, and economic implications given the cost of animal research. The current results can guide the development of future research methods and help investigators choose appropriate study timelines for various control groups.

Early Experience and Initial Outcomes With Patient-Specific Spine Rods for Adult Spinal Deformity.

The objectives of this study were to describe the process of preoperative planning and using patient-specific rods. This retrospective case series involved 18 patients with adult spinal deformity who were treated with posterior instrumentation and spine fusion, with lumbar or thoracic osteotomies, using patient-specific rods. Data extracted included demographic/surgical variables and preoperative, predicted (surgical plan), and postoperative spinopelvic parameters. The outcome analysis involved assessment of preoperative, planned, and postoperative variables. Treatment effect evaluation involved assessing differences between preoperative and postoperative values and correspondence between planned and achieved results. Surgery using preoperative planned patient-specific rods led to excellent adult spinal deformity correction and spinopelvic alignment.

Risk factors for rod fracture after posterior correction of adult spinal deformity with osteotomy: a retrospective case-series.

BACKGROUND: Osteotomies including pedicle subtraction (PSO) and/or Smith-Peterson (SPO) are used to facilitate surgical correction of adult spinal deformity (ASD), but are associated with complications including instrumentation failure and rod fracture (RF). The purpose of this study was to determine incidence and risk factors for RF, including a clinically significant subset (CSRF), after osteotomy for ASD. METHODS: A retrospective review of clinical records was conducted on consecutive ASD patients treated with posterolateral instrumented fusion and osteotomy. Seventy-five patients (50 female; average age, 59) met strict inclusion/exclusion criteria and follow-up of ≥1 year. Data was extracted pertaining to the following variables: patient demographics; details of surgical intervention; instrumentation; and postoperative outcomes. Patients were divided into two subgroups: 1) rod fracture (RF) and 2) non-RF. The RF subgroup was further divided into CSRF and non-CSRF. Odds ratios (OR) were calculated to evaluate the association between risk factors and RF. The χ (2)-test was used to define P-values for categorical variables, and T-test was applied for continuous variables, P-values ≤0.05 were considered significant. RESULTS: Incidence rates of RF were: for entire population, 9.3 % (95 % Cl: 2.7 %; 15.9 %); for PSO, 16.2 % (95 % Cl: 4.3; 28.1); and for SPO, 2.6 % (95 % Cl: 0 %; 7.7 %); the OR of PSO versus SPO was 7.2 (95 % Cl: 0.8; 62.7, P = 0.1). CSRF incidence was 5.3 % (95 % CI: 0.2 %; 10.4 %). Significant risk of RF was revealed for following factors: fusion construct crossing both thoracolumbar and lumbosacral junctions (OR = 9.1, P = 0.05), sagittal rod contour >60° (OR = 10.0, P = 0.04); the presence of dominos and/or parallel connectors at date of rod fracture (OR = 10.0, P = 0.01); and pseudarthrosis at ≥1 year follow-up (OR = 28.9, P < 0.001). Statistically significant risk of CSRF was revealed for fusion to pelvis (P = 0.05) and pseudarthrosis at ≥1 year follow-up (OR = 50.3, CI: 4.2; 598.8, P < 0.01). CONCLUSIONS: The risk of RF after posterolateral instrumented correction of ASD with osteotomy had statistically significant association with the following factors: pseudarthrosis at ≥1 year follow-up; sagittal rod contour >60°; presence of dominos and/or parallel connectors at date of fracture; and fusion construct crossing both thoracolumbar and lumbosacral junctions. Statistically significant risk for the CSRF subset was fusion to the pelvis and pseudarthrosis at ≥1 year follow-up.