Radiographic Cone Zone Classification of Metaphyseal Cone Fixation in Revision Total Knee Arthroplasty.

Background: No objective radiographic scoring system exists to classify metaphyseal cone stability. Our purpose was to create a novel, systematic method to radiographically evaluate metaphyseal cone fixation based on radiographic findings suggestive of cone stability. Methods: A retrospective analysis was conducted of revision total knee arthroplasty patients (6/2015-12/2017) using porous titanium femoral or tibial metaphyseal cones in conjunction with short cemented stems (50 mm-75 mm). Minimum follow-up was 2 years. Survivorship free of aseptic loosening and reoperation, as well as radiographic evaluation using a novel cone zone scoring system were analyzed. Results: Forty-nine revision total knee arthroplasties were included in the study (12 femoral, 48 tibial cones), the majority, performed for aseptic loosening (25/49, 51%). Median follow-up was 39 months (range 25-58). Using the radiographic cone zone scoring method, >90% of all femoral cones were classified as likely stable or stable with strong, statistically significant intraclass correlations between all 3 reviewers. Similarly, >97% of all tibial cones were classified as likely stable or stable, with moderate, statistically significant intraclass correlations between all 3 reviewers. Only 1 femoral and 1 tibial cone were considered at risk of loosening. The study sample demonstrated 100% survivorship free of revision for aseptic loosening without evidence of radiographic loosening in any case. Conclusions: Using a novel systematic cone zone scoring and classification method, the overwhelming majority of femoral and tibial cones were classified as likely stable or stable, with no identified cases of aseptic loosening or related revision. Further studies are needed to validate this objective classification method.

Risk Factors for Gram-Negative Fracture-Related Infection.

In this study, we evaluated risk factors for gram-negative fracture-related infection in a mixed cohort of gram-positive and gram-negative fracture-related infections to guide perioperative antibiotic prophylaxis for surgical fixation of fractures. We performed a retrospective review of all patients with fracture who were treated at an urban academic level I trauma center between February 1, 2012, and June 30, 2017. Inclusion criteria were as follows: (1) open or closed fracture with internal fixation; (2) deep, acute to subacute (<6 weeks), culture-positive fracture-related infection; and (3) age 18 years or older. Infections were classified as gram positive, gram negative, or polymicrobial. Demographic, surgical, and postoperative characteristics were compared among groups. Of 3360 patients, 43 (1.3%) had a fracture-related infection (15 gram negative, 14 gram positive, and 14 polymicrobial). Risk factors for gram-negative infection included initial external fixation (P=.038), the need for soft tissue coverage of an open fracture site (P=.039), lower albumin level at the time of infection (P=.005), and hospitalization for longer than 10 days (P=.018). Perioperative gram-negative antibiotic prophylaxis for fracture fixation surgery should be considered for those who have been staged with external fixation, require soft tissue coverage, are at risk for malnutrition in the postoperative period, and have prolonged inpatient hospitalization. [Orthopedics. 2022;45(2):91-96.].

Survivorship and Radiographic Evaluation of Metaphyseal Cones With Short Cemented Stems in Revision Total Knee Arthroplasty.

BACKGROUND: The purpose of this study is to evaluate the survivorship and radiographic outcomes of a single design of metaphyseal cone used in conjunction with short cemented stems. METHODS: A retrospective analysis was conducted of revision total knee arthroplasty (rTKA) patients (June 2015 to December 2017) using porous titanium femoral or tibial cones in conjunction with short cemented stems (50-75 mm). Minimum follow-up was 2 years. Survivorship, complications, and a modified Knee Society Radiographic score were analyzed. RESULTS: Forty-nine rTKAs were included in the study (12 femoral cones, 48 tibial cones). Varus-valgus constraint was used in 28 (57%) and a hinged bearing was used in 3 (6%) of these constructs. The majority were index rTKAs of primary components (86%), performed for aseptic loosening (51%) and reimplantation following staged treatment for infection (37%). Median follow-up was 39 months (range 25-58). Using a modified Knee Society Radiographic score, all constructs were classified as stable. Postoperatively, 4 rTKAs were complicated by recurrent infection (8%), periprosthetic fracture 2 (4%), and superficial wound infection 1 (2%). Seven rTKAs (14%) required reoperation. The majority of reoperations (4 rTKAs) were debridement and irrigation with implant retention for infection. Metaphyseal cone constructs with short cemented stems demonstrated 100% survivorship free of revision for aseptic loosening without evidence of radiographic loosening in any case. CONCLUSION: Our results demonstrate excellent outcomes with the use of metaphyseal cones with short cemented stems at mid-term follow-up. This construct avoids the use of long-stem fixation with the associated extraction difficulty, end of stem pain, and potential for malposition at the joint line. LEVEL OF EVIDENCE: IV, Case Series.

Posterior Malleolar Fixation Reduces the Incidence of Trans-Syndesmotic Fixation in Rotational Ankle Fracture Repair.

BACKGROUND: Inaccuracy of ankle syndesmotic repair via reduction and trans-syndesmotic fixation can occur during ankle fracture repair. The goal of this study was to determine whether reduction and fixation of the posterior malleolar fracture (PM) fragment in rotational ankle fractures reduces the need for independent syndesmotic screw fixation. METHODS: A retrospective study was conducted using a consecutive series of patients treated operatively for a rotationally unstable ankle fracture with a PM fragment between 2011-2017. All ankle fractures underwent open reduction and internal fixation and divided into two groups: PM fixed or not fixed. An intraoperative stress evaluation of the ankle following bony fixation was performed in all cases to evaluate syndesmotic instability. Patient and fracture characteristics, and intraoperative instability and trans-syndesmotic fixation were compared between both groups. RESULTS: Eighty-five unstable ankle fractures that had a PM fragment were identified. Forty-three fractures underwent PM fixation and 42 did not. There were no differences between the PM fixation groups with regard to age, gender, body mass index or fracture pattern (p>0.183 for all). On average, PM fragments in the fixed group were larger than those not fixed (p<0.001). There were significantly lower odds of needing syndesmotic fixation if the PM fragment was reduced and fixed (p<0.001). Only 2 out of 43 ankles with a fixed PM fragment underwent syndesmotic fixation compared with 34 out of 42 non-fixed PM fragments. CONCLUSION: Posterior malleolar fixation imparts syndesmotic stability and may obviate the need for trans-syndesmotic fixation for restoring dynamic ankle mortise congruence.Level of Evidence: III.

Cementless Primary Total Knee Arthroplasty Will this be the Future?

Cementless fixation in total knee arthroplasty (TKA) offers the potential for biologically active osseointegration and the potential for life-long fixation. With early cementless TKA designs, several design issues were identified related to early failure, particularly with the tibial and patellar components. However, in the recent two decades, with improvements upon the early designs, particularly in porous metal technology as well as improved early biomechanical stability, interest was re-established in cementless TKA. The surgical technique for cementless TKA is more exacting than cemented technique, with an important emphasis on indications, accurate resections, and component alignment. Modern cementless TKA designs have demonstrated excellent early- and mid-term survivorship equivalent to cemented TKA. More long-term studies are needed to study this comparison. While implant cost maybe higher with cementless designs, there is emerging evidence that there may be an overall cost saving with the use of cementless components given the shorter operative time and the savings in the cost of supplies associated with the use of cement. As the population undergoing TKA is becoming younger and more active, interest in the use of cementless implants will likely increase.

The Importance of Appropriate Incision Choice in Conversion Total Knee Arthroplasty.

When faced with the necessity of surgery in a previously operated knee, pre-operative planning and understanding of the vascular anatomy to the front of the knee is essential. Blood flow to the anterior aspect of the knee comes from medial to lateral. Therefore, in the case of multiple previous knee incisions the most lateral incision should always be chosen to avoid skin necrosis. The concept of a safe distance between incisions is inappropriate, risks extensive skin necrosis, and should be abandoned. (Journal of Surgical Orthopaedic Advances 30(4):253-255, 2021).

Aseptic Loosening of Porous Metaphyseal Sleeves and Tantalum Cones in Revision Total Knee Arthroplasty: A Systematic Review.

Bone loss often complicates revision total knee arthroplasty (TKA). Management of metaphyseal defects varies, with no clearly superior technique. Two commonly utilized options for metaphyseal defect management include porous-coated metaphyseal sleeves and tantalum cones. A systematic review was conducted according to the international Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We combined search terms "Total knee arthroplasty" AND/OR "Sleeve," "Cone" as either keywords or medical subject heading (MeSH) terms in multiple databases according to PRISMA recommendations. All retrieved articles were reviewed and assessed using defined inclusion and exclusion criteria. A total of 27 studies (12 sleeves and 15 cones) of revision TKAs were included. In the 12 studies on sleeve implantation in revision TKAs, 1,617 sleeves were implanted in 1,133 revision TKAs in 1,025 patients. The overall rate of reoperation was 110/1,133 (9.7%) and the total rate of aseptic loosening per sleeve was 13/1,617 (0.8%). In the 15 studies on tantalum cone implantation in revision TKAs, 701 cones were implanted into 620 revision TKAs in 612 patients. The overall rate of reoperation was 116/620 (18.7%), and the overall rate of aseptic loosening per cone was 12/701 (1.7%). Rates of aseptic loosening of the two implants were found to be similar, while the rate of reoperation was nearly double in revision TKAs utilizing tantalum cones. Variability in the selected studies and the likely multifactorial nature of failure do not allow for any definitive conclusions to be made. This review elucidates the necessity for additional literature examining revision TKA implants.

Hip Fracture Volume Does Not Change at a New York City Level 1 Trauma Center During a Period of Social Distancing.

PURPOSE: To characterize the volume and variation in orthopedic consults and surgeries that took place during a period of social distancing and pandemic. METHODS: All orthopedic consults and surgeries at an urban level 1 trauma center from 3/22/20-4/30/2020 were retrospectively reviewed (the social distancing period). Data from the same dates in 2019 were reviewed for comparison. Age, gender, Score for Trauma Triage in the Geriatric and Middle Aged (STTGMA) score and injury type were queried. Operating room data collected included: type of surgery performed, inpatient or outpatient status, and if the cases were categorized as elective, trauma or infectious cases. RESULTS: Compared to 2019, there was a 48.3% decrease in consult volume in 2020. The 2020 population was significantly older (44.0 vs 52.6 years-old, p = 0.001) and more male (65% vs 35%, p = 0.021). There were 23 COVID positive patients, 10 of which died within the collection period. Consult distribution dramatically changed, with decreases in ankle fractures, distal radius fractures and proximal humerus fractures of 76.5%, 77.4% and 55.0%, respectively. However, there was no significant difference in volume of hip, tibial shaft and femoral shaft fractures (p > 0.05). In 2020, there was a 41.4% decrease in operating room volume, no elective cases were performed, and cases were primarily trauma related. CONCLUSIONS: During a period of pandemic and social distancing, the overall volume of orthopedic consults and surgeries significantly declined. However, hip fracture volume remained unchanged. Patients presenting with orthopedic injuries were older, and at higher risk for inpatient mortality.

Patterns and Implications of Early Syndesmotic Screw Failure in Rotational Ankle Fractures.

BACKGROUND: The purpose of this study was to identify characteristic patterns of syndesmotic screw (SS) failure, and any effects on clinical outcome. METHODS: A retrospective study was performed using a consecutive series of patients treated with open reduction and internal fixation with trans-syndesmotic screws for unstable ankle fractures with syndesmotic injury between 2015 and 2017. Patient demographics, fracture characteristics and classification, rates and patterns of trans-syndesmotic screw breakage, and backout were analyzed. Functional outcome was assessed using passive range of motion (ROM) and Maryland Foot Score (MFS). RESULTS: A total of 113 patients (67%) had intact screws and 56 patients (33%) demonstrated either screw breakage or backout. Patients with SS failure were younger (P = .002) and predominantly male (P = .045). Fracture classification and energy level of injury were not associated with screw failure. Nine screws (11%) demonstrated backout (2 also broke) and 56 other screws broke. There was no association between the number of screws or cortices of purchase and screw failure. There was a trend toward a higher proportion of screw removal (20%) in this failed SS group compared with the intact SS group (12%) (P = .25), but with similar ankle ROM and MFS (P > .07). CONCLUSION: Syndesmotic screw breakage was common in younger, male patients. Despite similarities in ankle range of motion and clinical outcome scores to patients with intact screws, there was a trend towards more frequent screw removal. This information can be used to counsel patients pre- and postoperatively regarding the potential for screw failure and subsequent implant removal. LEVEL OF EVIDENCE: Level III, retrospective case-control study.

Can Flexed-Seated and Single-Leg Standing Radiographs Be Useful in Preoperative Evaluation of Lumbar Mobility in Total Hip Arthroplasty?

BACKGROUND: The purpose of this study is to determine whether simulated radiographs in the "flexed-seated" or "step-up" positions better demonstrate a patient's range of spinopelvic motion between standing and sitting positions than relaxed sitting and standing radiographs. METHODS: An institutional review board approved cohort of 43 patients with hip osteoarthritis whom underwent full body sitting-standing radiographs from August 2016 to December 2017 at a single institution was reviewed. Subjects underwent single-leg step-up standing and flexed-seated radiographs, and relaxed standing and sitting radiographs. Sacral slope, spinopelvic tilt (SPT), and lumbar lordosis were measured in all radiographs. Alignment parameters were compared between both sets of imaging, and the change in SPT between the imaging modalities was plotted and stratified by pre-existing lumbar pathology. RESULTS: There were significant differences between the relaxed standing and step-up radiographs and the relaxed and flexed-seated radiographs for sacral slope, SPT, and lumbar lordosis (P < .002 for all), with the exception of SPT in the relaxed and step-up standing postures (P = .110). When transitioning from the standing to sitting position, the mean changes in SPT differed significantly between both sets of radiographs. Most importantly, when plotting changes in SPT between flexed and relaxed sitting postures, patients with fusions and flatback deformity trended toward greater anterior pelvic tilting, a position of greater risk of posterior dislocation. CONCLUSION: Flexed sitting and single-leg standing imaging may emphasize the compensatory mechanisms of patients with concomitant hip and spine pathology more than relaxed imaging using our measurements. Our method may provide insight into high dislocation risk patients compared to the previously published hip measurement method. LEVEL OF EVIDENCE: III.

Total Hip Arthroplasty for Femoral Neck Fracture in the Setting of Challenging Extraction of an Intramedullary Femoral Nail: A Case Report.

INTRODUCTION: Performing total hip arthroplasty (THA) for femoral neck fracture in the setting of a pre-existing intramedullary nail can be technically challenging, particularly if nail extraction is not feasible. CASE REPORT: A 76-year-old male presented with a with a displaced femoral neck fracture in the setting of a previously placed antegrade intramedullary nail with a healed femoral shaft fracture. After failed nail extraction, a novel technique was used to remove the proximal portion of the nail to allow for hybrid THA with implantation of a cemented femoral stem. CONCLUSION: This is the first reported surgical technique of using a cortical window technique for partial intramedullary nail resection and cemented stem implantation in the setting of challenging intramedullary femoral nail extraction.

Patellofemoral Arthroplasty: Short-Term Complications and Risk Factors.

There is a paucity of literature regarding the short-term readmission, reoperation, and complication rates of patellofemoral arthroplasty (PFA). The purpose of this study is to determine the incidence and risk factors of 30-day postoperative complications in patients undergoing PFA. A retrospective cohort study of subjects who underwent PFA from 2010 to 2015 was performed using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. Perioperative outcomes and 30-day postoperative complications were ascertained, and patient demographics and comorbidities were analyzed using linear and binomial logistic regression analyses to determine risk factors for postoperative complications. Among the 1,069 patients identified in the NSQIP database, there was a 30-day readmission rate of 4.3% and a 30-day reoperation rate of 1.5%. The leading complications identified were bleeding requiring transfusion (11.7%), urinary tract infection (0.8%), and deep vein thrombosis (DVT) (0.8%). Younger age was a risk factor for superficial wound infection (p = 0.012). Older age was a significant risk factor for longer hospital stays, readmission, bleeding requiring transfusion, urinary tract infection, and pneumonia (p < 0.05 for all). Male sex was a risk factor for longer operation time and DVT (p = 0.001 and p = 0.017, respectively), while female sex was associated with greater incidence of bleeding requiring transfusion (p = 0.049). Elevated body mass index (BMI) was a risk factor for longer hospital stays, greater total operation time, and bleeding requiring transfusion (p < 0.001, p < 0.001, and p = 0.001, respectively). Nonwhite race was a significant risk factor for readmission (p = 0.008). This represents the largest study on early readmissions and the associated risk factors after PFA. PFA 30-day readmission and reoperation rates were <5%. Older age and elevated BMI were both identified as risk factors for adverse perioperative outcomes, including longer operation times, longer hospital stays, and bleeding requiring transfusion.

The prevalence of elevated-rim polyethylene liner use in primary total hip arthroplasty in the New York State metropolitan area.

In existing radiographic studies on primary total hip arthroplasty (THA) examining the spino-pelvic effect on THA instability, there is no control of the type of polyethylene liner used, which may be a significant confounder of the results. We sought to determine the prevalence of the use of elevated liners in primary THA using regional implant company sales data. A total of 12,528 liners were analyzed, demonstrating that the overall regional percentage use of lipped liner use is high and varies inversely with larger head sizes. This prevalence data suggests that it is important to consider the use of lipped liners as a confounding variable that should not be overlooked in radiographic studies analyzing cup position and THA instability.

Suboptimal Age-Adjusted Lumbo-Pelvic Mismatch Predicts Negative Cervical-Thoracic Compensation in Obese Patients.

BACKGROUND: Given the paucity of literature regarding compensatory mechanisms used by obese patients with sagittal malalignment, it is necessary to gain a better understanding of the effects of obesity on compensation after comparing the degree of malalignment to age-adjusted ideals. This study aims to compare baseline alignment of obese and nonobese patients using age-adjusted spino-pelvic alignment parameters, describing associated spinal changes. METHODS: Patients ≥ 18 years with full-body stereoradiographs were propensity-score matched for sex, baseline pelvic incidence (PI), and categorized as nonobese (body mass index < 30kg/m2) or obese (body mass index ≥ 30). Age-adjusted ideals were calculated for sagittal vertical axis, spino-pelvic mismatch (PI-LL), pelvic tilt, and T1 pelvic angle using established formulas. Patients were stratified as meeting alignment ideals, being above ideal, or being below. Spinal alignment parameters included C0-C2, C2-C7, C2-T3, cervical thoracic pelvic angle, cervical sagittal vertical axis SVA, thoracic kyphosis, T1 pelvic angle, T1 slope, sagittal vertical axis, lumbar lordosis (LL), PI, PI-LL, pelvic tilt. Lower-extremity parameters included sacrofemoral angle, knee flexion (KA), ankle flexion (AA), pelvic shift (PS), and global sagittal angle (GSA). Independent t tests compared parameters between cohorts. RESULTS: Included: 800 obese, 800 nonobese patients. Both groups recruited lower-extremity compensation: sacrofemoral angle (P = .004), KA, AA, PS, GSA (all P < .001). Obese patients meeting age-adjusted PI-LL had greater lower-extremity compensation than nonobese patients: lower sacrofemoral angle (P = .002), higher KA (P = .008), PS (P = .002), and GSA (P = .02). Obese patients with PI-LL mismatch higher than age-adjusted ideal recruited greater lower-extremity compensation than nonobese patients: higher KA, AA, PS, GSA (all P < .001). Obese patients showed compensation through the cervical spine: increased C0-C2, C2-C7, C2-T3, and cervical sagittal vertical axis (all P < .001), high T1 pelvic angle (P < .001), cervical thoracic pelvic angle (P = .03), and T1 slope (P < .001), with increased thoracic kyphosis (P = .015) and decreased LL (P < .001) compared to nonobese patients with PI-LL larger than age-adjusted ideal. CONCLUSIONS: Regardless of malalignment severity, obese patients recruited lower-limb compensation more than nonobese patients. Obese patients with PI-LL mismatch larger than age-adjusted ideal also develop upper-cervical and cervicothoracic compensation for malalignment. LEVEL OF EVIDENCE: III. CLINICAL RELEVANCE: Clinical evaluation should extend to the cervical spine in obese patients not meeting age-adjusted sagittal alignment ideals.

Patterns and Costs of 90-Day Readmission for Surgical and Medical Complications Following Total Hip and Knee Arthroplasty.

BACKGROUND: Unplanned readmissions following elective total hip (THA) and knee (TKA) arthroplasty as a result of surgical complications likely have different quality improvement targets and cost implications than those for nonsurgical readmissions. We compared payments, timing, and location of unplanned readmissions with Center for Medicare and Medicaid Services (CMS)-defined surgical complications to readmissions without such complications. METHODS: We performed a retrospective analysis on unplanned readmissions within 90 days of discharge following elective primary THA/TKA among Medicare patients discharged between April 2013 and March 2016. We categorized unplanned readmissions into groups with and without CMS-defined complications. We compared the location, timing, and payments for unplanned readmissions between both readmission categories. RESULTS: Among THA (N = 23,231) and TKA (N = 43,655) patients with unplanned 90-day readmissions, 27.1% (n = 6307) and 16.4% (n = 7173) had CMS-defined surgical complications, respectively. These readmissions with surgical complications were most commonly at the hospital of index procedure (THA: 84%; TKA: 80%) and within 30 days postdischarge (THA: 73%; TKA: 77%). In comparison, it was significantly less likely for patients without CMS-defined surgical complications to be rehospitalized at the index hospital (THA: 63%; TKA: 63%; P < .001) or within 30 days of discharge (THA: 58%; TKA: 59%; P < .001). Generally, payments associated with 90-day readmissions were higher for THA and TKA patients with CMS-defined complications than without (P < .001 for all). CONCLUSION: Readmissions associated with surgical complications following THA and TKA are more likely to occur at the hospital of index surgery, within 30 days of discharge, and cost more than readmissions without CMS-defined surgical complications, yet they account for only 1 in 5 readmissions.

Single- vs 2-Screw Lag Fixation of the Medial Malleolus in Unstable Ankle Fractures.

BACKGROUND: The purpose of this study was to determine the efficacy of medial malleolar fixation with 1 vs 2 screws. METHODS: Between April 2013 and February 2017, 196 patients who presented at 2 hospitals within one academic institution with an unstable rotational ankle fracture with a medial fracture and were treated operatively by a trained orthopedic surgeon were identified. These patients' charts were reviewed and their injury, radiographic, surgical, and follow-up data recorded. Medial malleolus fragment size was assessed on the anteroposterior (AP) and lateral views of the initial injury radiograph. Functional outcome was assessed using Maryland Foot Score (MFS). Patients were grouped based upon the number of screws utilized to fox the medial malleolar fragment. Data were assessed using Fisher exact tests and independent t tests with SPSS, version 23. RESULTS: Out of the 196 patients who met inclusion criteria, 47 patients (24%) were fixed with 1 medial malleolar screw and 149 patients (76%) were fixed with 2 screws. There were no differences among patients who received 1 vs 2 screws with regard to age, gender, body mass index, American Society of Anesthesiologists grade, or smoking status. The average malleolar fragment size was smaller in those treated with 1 screw on both the AP and lateral radiographic views than those with 2 screws (P = .009, P = .001, respectively). There was no difference between groups in ankle dorsiflexion or plantarflexion at 1 year postoperation (P = .451, P = .581). Patients who received 1 screw did not differ from those who received 2 screws with respect to Maryland Foot Scores (P = .924). There was no difference in rate of revision surgery or need for hardware removal between groups (P = .093). Furthermore, time to healing and postoperative complication rate did not differ between groups. CONCLUSION: The use of a single screw for medial malleolar fixation provided stable fixation to allow ankle fracture healing, without an increase in complications. This information is especially important in situations when the fragment is too small to accommodate multiple fixation points. LEVEL OF EVIDENCE: Level III, retrospective case-control study.

The Effect of Total Knee Arthroplasty on Physical Activity and Body Mass Index: An Analysis of the Osteoarthritis Initiative Cohort.

INTRODUCTION: Preliminary analysis of accelerometry measurements has shown physical activity may not increase significantly after total knee arthroplasty (TKA). This study evaluates the effect of TKA on physical activity accelerometry measurements and body mass index (BMI). METHODS: Using the multicenter Osteoarthritis Initiative (OAI) database, a cohort of patients with physical activity level accelerometry measurements and BMI before and after TKA was identified. Physical activity levels and BMI were acquired at pre-TKA and post-TKA accelerometry visits 2 years apart. Survey scores pertaining to knee functionality and quality of life were also analyzed before and after knee surgery. Each patient included in the study had a unilateral TKA completed between these 2 accelerometry visits. Accelerometry measurements, BMI of the patients, and survey scores relating to knee functionality and pain relief from before and after TKA were compared using paired samples t tests. RESULTS: Twenty-three patients from the OAI database were identified for the paired analysis. They were evaluated at a mean postoperative follow-up of 15 months. There were no statistically significant differences between the post-TKA group and pre-TKA group for the accelerometry variables and BMI, though patients experienced a significant improvement in knee function and pain relief measures included in this analysis. DISCUSSION: Although TKA can successfully restore function and relieve pain, there remains no good evidence that neither physical activity nor BMI improve postoperatively. CONCLUSION: No significant differences in physical activity and BMI were observed after TKA in this study.

What are the prevalence and risk factors for repeat ipsilateral knee arthroscopy?

PURPOSE: The number of arthroscopic knee surgeries performed annually has increased over the last decade. It remains unclear what proportion of individuals undergoing knee arthroscopy is at risk for subsequent ipsilateral procedures. Better knowledge of risk factors and the incidence of reoperative ipsilateral arthroscopy are important in setting expectations and counselling patients on treatment options. The aim of this study is to determine the incidence of repeat ipsilateral knee arthroscopy, and the risk factors associated with subsequent surgery over long-term follow-up. METHODS: The New York Statewide Planning and Research Cooperative Systems outpatient database was reviewed from 2003 to 2016 to identify patients who underwent elective, primary knee arthroscopy for one of the following diagnosis-related categories of procedures: Group 1: cartilage repair and transfer; Group 2: osteochondritis dissecans (OCD) lesions; Group 3: meniscal repair, debridement, chondroplasty, and synovectomy; Group 4: multiple different procedures. Subjects were followed for 10 years to determine the odds of subsequent ipsilateral knee arthroscopy. Risk factors including the group of arthroscopic surgery, age group, gender, race, insurance type, surgeon volume, and comorbidities were analysed to identify factors predicting subsequent surgery. RESULTS: A total of 765,144 patients who underwent knee arthroscopy between 2003 and 2016, were identified. The majority (751,873) underwent meniscus-related arthroscopy. The proportion of patients undergoing subsequent ipsilateral knee arthroscopy was 2.1% at 1-year, 5.5% at 5 years, and 6.7% at 10 years of follow-up. Among patients who underwent subsequent arthroscopic surgery at 1-, 5-, and 10-year follow-up, there was a greater proportion of patients with worker's compensation insurance (p < 0.001), index operations performed by very high volume surgeons (p < 0.001), and cartilage restoration index procedures (p < 0.001), compared with those who never underwent repeat ipsilateral surgery. CONCLUSION: Understanding the incidence of subsequent knee arthroscopy after index procedure in different age groups and the patterns over 10 years of follow-up is important in counselling patients and setting future expectations. The majority of subsequent surgeries occur within the first 5 years after index surgery, and subjects tend to have higher odds of ipsilateral reoperation for up to 10 years if they have worker's compensation insurance, or if their index surgery was performed by a very high volume surgeon, or was a cartilage restoration procedure. LEVEL OF EVIDENCE: III.