Survivorship and Etiologies of Failure in Single-stage Revision Arthroplasty for Periprosthetic Joint Infection: A Meta-analysis.

INTRODUCTION: Single-stage revision arthroplasty for periprosthetic joint infection (PJI) may yield comparable infection-free survivorship with two-stage revision arthroplasty. It is unclear if the most common mode of failure of single-stage revision arthroplasty is infection or aseptic loosening. In this meta-analysis, we sought to (1) determine survivorship and (2) compare rates of different etiologies of failure of single-stage revision total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: Preferred Reporting Items for Systematic Review and Meta-analyses guidelines search was done using search terms for "single stage revision," "exchange arthroplasty," "periprosthetic infection," "PJI," and "single stage." Patient demographics such as age, body mass index, and mean follow-up time were recorded. Overall survivorship and rates of revision surgery were aggregated using a random-effects model. Comparison of septic and aseptic loosening rates was done by risk difference and associated 95% confidence interval (CI) calculation. RESULTS: Twenty-four studies were identified with 2,062 and 147 single-stage revision THA and TKA procedures performed between 1984 and 2019, respectively. The weighted mean follow-up and age were 69.8 months and 66.3 years, respectively, with 55% men overall. The all-cause revision surgery rate was 11.1% and 11.8% for THA and TKA, respectively. The revision surgery rate secondary to infection and aseptic loosening and associated 95% CI for the risk difference for THA and TKA was 5.5% and 3.3% (-1.7% to 5.0%), and 3% and 8.8% (-11.4% to 2.3%), respectively. Revision surgeries due to instability and fracture combined and mortality rate were both less than 3%. DISCUSSION: Single-stage revision THA and TKA for PJI demonstrated overall high rates of survivorship, low mortality, and revision surgeries secondary to infection and aseptic loosening to be equivalent. Aseptic loosening after single-stage revision TKA might be higher than in primary TKA. As implant survivorship from infection improves in PJI, surgeons should be aware of aseptic loosening as an equally common mode of failure.

Tantalum Cementless Versus Cemented Total Knee Arthroplasty: A Meta-analysis of Level 1 Studies.

INTRODUCTION: Controversy exists on the ideal type of fixation in total knee arthroplasty (TKA). Noncemented fixation has been theorized to improve patient outcomes and longevity of implantation without increased risk of aseptic loosening or radiolucent lines. We sought to compare (1) patient-reported outcomes, (2) survivorship, and (3) revision rates for all-cause and aseptic loosening in a noncemented tantalum total knee with its cemented counterpart. METHODS: Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines were searched using a combination of keywords "trabecular metal," "tantalum knee," "total knee arthroplasty," and "cementless trabecular." Patient demographics such as age, sex, and body mass index were collected. Outcomes such as Knee Society Scores (KSSs), revisions, and radiolucent lines were recorded for analysis. RESULTS: Four randomized controlled trials involving 507 patients with an average 5-year follow-up were eligible for meta-analysis. No differences were observed in any demographics such as age, sex, body mass index, nor preoperative KSS. Patients in the cemented cohort improved from preoperative KSS 46.4 to postoperative KSS 90.4 while the tantalum cohort improved from 46.4 to 89.3. No statistical difference was observed in postoperative KSS mean difference between groups. Six patients from the tantalum group underwent revision with one patient for aseptic loosening. Twelve patients from the cemented group underwent revision with four patients for aseptic loosening. No statistical difference was observed between rates of revision, aseptic loosening, or radiolucent line development. DISCUSSION: Patient-reported outcomes improved postoperatively in both groups. No differences were detected between the cemented and noncemented TKAs in patient-reported outcomes, revision rates, or radiolucent line development. Noncemented tantalum fixation seems equivalent to cemented TKA survivorship. Longer term follow-up of these randomized controlled trials may provide a clearer understanding whether a difference exists.

Older Patients More Accurately Predict Pain Tolerance After Lumbar Spine Fusion Compared with Their Younger Peers.

OBJECTIVE: Patients undergoing spine surgery often inaccurately estimate their pain tolerance and postoperative analgesic requirement. We sought to identify an association between patients' self-perceived pain tolerance and postoperative opioid consumption (POC). METHODS: We included adult patients undergoing elective lumbar spine decompression and fusion between 2014 and 2018. Patients with cognitive delay, psychiatric comorbidities, and perioperative complications were excluded. Demographic data, mean daily postoperative morphine milligram equivalents (MME), and pain tolerance scores were recorded. RESULTS: Eighty-four patients met inclusion criteria. The median pain tolerance score was 8, which was used to defined a cutoff for high (≥8) and low (<8) pain tolerance. The average preoperative visual analog scale (VAS) pain score was higher in the high pain tolerance group (µ = 5.3) compared with the low pain tolerance group (µ = 4.0) (P = 0.01). Multivariate regression revealed pain tolerance was not predictive of mean daily postoperative MME use (P = 0.19). Age and preoperative VAS pain score were found to be negative (P < 0.0001) and positive (P = 0.027) independent predictors, respectively, of mean postoperative MME use. Patients 61 years and younger who reported high pain tolerance had higher POC compared with patients older than 61 years of age, who reported low (P = 0.036) pain tolerance. CONCLUSIONS: Self-perceived pain tolerance does not appear to predict POC, while younger age and higher preoperative VAS pain scores are related to increased POC. Younger patients who report high pain tolerance appear to consume higher levels of opioids compared with older patients.

Salter-Harris type II fractures of the distal tibia: Residual postreduction displacement and outcomes-a STROBE compliant study.

We assessed factors associated with premature physeal closure (PPC) and outcomes after closed reduction of Salter-Harris type II (SH-II) fractures of the distal tibia. We reviewed patients with SH-II fractures of the distal tibia treated at our center from 2010 to 2015 with closed reduction and a non-weightbearing long-leg cast. Patients were categorized by immediate postreduction displacement: minimal, <2 mm; moderate, 2 to 4 mm; or severe, >4 mm. Demographic data, radiographic data, and Lower Extremity Functional Scale (LEFS) scores were recorded.Fifty-nine patients (27 girls, 31 right ankles, 26 concomitant fibula fractures) were included, with a mean (±SD) age at injury of 12.0 ±â€Š2.2 years. Mean maximum fracture displacements were 6.6 ±â€Š6.5 mm initially, 2.7 ±â€Š2.0 mm postreduction, and 0.4 ±â€Š0.7 mm at final follow-up. After reduction, displacement was minimal in 23 patients, moderate in 21, and severe in 15. Fourteen patients developed PPC, with no significant differences between postreduction displacement groups. Patients with high-grade injury mechanisms and/or initial displacement ≥4 mm had 12-fold and 14-fold greater odds, respectively, of PPC. Eighteen patients responded to the LEFS survey (mean 4.0 ±â€Š2.1 years after injury). LEFS scores did not differ significantly between postreduction displacement groups (P = .61).The PPC rate in this series of SH-II distal tibia fractures was 24% and did not differ by postreduction displacement. Initial fracture displacement and high-grade mechanisms of injury were associated with PPC. LEFS scores did not differ significantly by postreduction displacement.Level of Evidence: Level IV, case series.

Fracture Patterns Differ Between Osteogenesis Imperfecta and Routine Pediatric Fractures.

BACKGROUND: It is important to estimate the likelihood that a pediatric fracture is caused by osteogenesis imperfecta (OI), especially the least severe type of OI (type 1). METHODS: We reviewed records of 29,101 pediatric patients with fractures from 2003 through 2015. We included patients with closed fractures not resulting from motor vehicle accidents, gunshot wounds, nonaccidental trauma, or bone lesions. Patients with OI of any type were identified through International Classification of Diseases-9 code. We randomly sampled 500 pediatric patients in whom OI was not diagnosed to obtain a control (non-OI) group. We reviewed age at time of fracture, sex, fracture type, laterality, and bone and bone region fractured. Bisphosphonate use and OI type were documented for OI patients. Subanalysis of patients with type-1 OI was performed. The Fisher exact and χ tests were used to compare fracture rates between groups. P<0.05 was considered significant. Positive likelihood ratios for OI were calculated by fracture pattern. RESULTS: The non-OI group consisted of 500 patients with 652 fractures. The OI group consisted of 52 patients with 209 fractures. Non-OI patients were older at the time of fracture (mean, 9.0±5.0 y) than OI patients (mean, 5.5±4.4 y) (P<0.001). OI patients had more oblique, transverse, diaphyseal, and bilateral long-bone fractures than non-OI patients (all P<0.001). Non-OI patients had more buckle (P=0.013), metaphyseal (P<0.001), and physeal (P<0.001) fractures than OI patients. For patients with type-1 OI and long-bone fractures (n=18), rates of transverse and buckle fractures were similar compared with controls. Transverse humerus (15.2), olecranon (13.8), and diaphyseal humerus (13.0) fractures had the highest positive likelihood ratios for OI, and physeal (0.09) and supracondylar humerus (0.1) fractures had the lowest. CONCLUSIONS: Transverse and diaphyseal humerus and olecranon fractures were most likely to indicate OI. Physeal and supracondylar humerus fractures were least likely to indicate OI. Radiographic fracture pattern is useful for estimating likelihood of OI. LEVEL OF EVIDENCE: Level III.

Development of novel 3D-printed robotic prosthetic for transradial amputees.

BACKGROUND AND AIM: Upper extremity myoelectric prostheses are expensive. The Robohand demonstrated that three-dimensional printing reduces the cost of a prosthetic extremity. The goal of this project was to develop a novel, inexpensive three-dimensional printed prosthesis to address limitations of the Robohand. TECHNIQUE: The prosthesis was designed for patients with transradial limb amputation. It is shoulder-controlled and externally powered with an anthropomorphic terminal device. The user can open and close all five fingers, and move the thumb independently. The estimated cost is US$300. DISCUSSION: After testing on a patient with a traumatic transradial amputation, several advantages were noted. The independent thumb movement facilitated object grasp, the device weighed less than most externally powered prostheses, and the size was easily scalable. Limitations of the new prosthetic include low grip strength and decreased durability compared to passive prosthetics. CLINICAL RELEVANCE: Most children with a transradial congenital or traumatic amputation do not use a prosthetic. A three-dimensional printed shoulder-controlled robotic prosthesis provides a cost effective, easily sized and highly functional option which has been previously unavailable.