Hip fractures are prevalent among the elderly population and are correlated with notable morbidity and mortality. Treatment with intramedullary nails has risen in popularity with good results, however complications can occur. We report on a 62-year-old female with a body mass index of 63 kg/m2 who presents with cephalomedullary nail lag screw migration following an open reduction and internal fixation of an intertrochanteric fracture, which was subsequently converted to a hip hemiarthroplasty after hardware failure of her cephalomedullary nail. Proper radiographic follow-up is essential for catching the complication early and preventing further injury. Hemiarthroplasty is an appropriate next step when facing this complication.

While peripheral nerve schwannomas have a relatively low incidence, schwannomatosis, the condition in which one forms multiple recurring schwannomas, is an even rarer phenomenon and can be hard to detect given its ability to mimic other conditions. We report a case of a 35-year-old male who presented with a mass in his left wrist and forearm, volar pain in his forearm, and numbness in his fingers. Magnetic resonance imaging (MRI) revealed a bilobed heterogeneous neural sheath tumor in the distal left ulnar nerve. The tumor was resected including extensive internal neurolysis using a Zeiss operative microscope. Post-operative biopsy confirmed an encapsulated schwannoma. The patient did well initially but developed worsening pain in his forearm and weakness. He had persistent paresthesias in the ulnar nerve distribution. He underwent a repeat MRI almost one year later, which showed thickening of the ulnar nerve proximal to the area of resection with an 8.5 mm hyperintense nodule. The patient underwent a subsequent resection with extensive neurolysis, which confirmed that the mass was a benign non-invasive schwannoma. At six weeks post-surgery, the patient's forearm pain was significantly improved and his range of motion returned to baseline. Our case demonstrates the importance of post-operative follow-up in schwannomas with appropriate imaging if symptoms persist or recur.

Objectives There is a paucity of literature investigating the relationship between patellar fracture and player performance of professional soccer players following return to play (RTP). Our goal is to determine the rate of RTP, time to RTP, and effect on player performance following patellar fracture. Methods Twenty-one elite-level European professional soccer players who sustained a patellar fracture between 1999 and 2018 were identified via a publicly accessible database. Athletes with patellar fracture were matched to controls by age, height, years played in the league, season of injury, and position. Change in performance metrics between one season prior to injury and the following four seasons after injury were compared. Results Players with patellar fracture were absent for a mean 207.95 +/- 135.55 days and 16.81 +/- 31.79 games. Fifteen (71%) players returned to play after injury with 67% returning within 1 season after injury. Injured players did not demonstrate significant change in performance metrics at any of the follow-up timepoints compared to control. Subgroup analysis showed that attackers recorded approximately 1200 fewer minutes played per season than pre-injury levels 2 seasons following injury, significantly fewer (p < 0.05) than the control cohort recording similar minutes per season throughout the study period. Midfielders and defenders demonstrated similar fluctuations in performance to the control cohort for both field time and performance metrics (p > 0.05). Conclusion Seventy-one percent of players RTP after patellar fracture with an associated absence of 7 months and 17 missed games. Overall, injured players did not demonstrate a significant decline in performance as demonstrated by games played, total minutes played per season, minutes per game, assists, and goals 1 season after injury. Attackers played fewer minutes during the season of and 2 seasons after the initial injury.

Introduction: Clinical decision-making is highly based on expert opinion. Machine learning is increasingly used to develop patient-specific risk prediction analysis to improve patient selection prior to surgery. Objectives: To develop machine learning algorithms to predict failure of surgical procedures that address cartilage defects of the knee and detect variables associated with failure. Methods: An institutional database was queried for cartilage procedures performed between 2000 and 2018. Failure was defined as revision cartilage surgery or knee arthroplasty. One hundred and one preoperative and intraoperative features were evaluated as potential predictors. Four machine learning algorithms were trained and internally validated. Results: One thousand and ninety-one patients with a minimum follow-up of 2 years were included and underwent chondroplasty (n = 560; 51%), osteochondral allograft transplantation (n = 306; 28%), microfracture (n = 150; 14%), autologous chondrocyte implantation (n = 39; 4%), or osteochondral autograft transplantation (n = 36; 3%). The Random Forest algorithm was the best-performing algorithm, with an area under the curve of 0.765 and a Brier score of 0.135. The most important features for predicting failure were symptom duration, age, body mass index, lesion grade, and total lesion area. Local Interpretable Model-agnostic Explanations analysis provided patient-specific comparisons for the risk of failure of an individual patient being assigned various types of cartilage procedures. Conclusions: Machine learning algorithms were accurate in predicting the risk of failure following cartilage procedures of the knee, with the most important features in descending order being symptom duration, age, body mass index, lesion grade, and total lesion area. Machine learning algorithms may be used to compare the risk of failure of specific patient-procedure combinations in the treatment of cartilage defects of the knee.

Objectives: To develop machine learning algorithms to predict failure of surgical procedures that address cartilage defects of the knee and detect the most valuable variables associated with failure. Methods: A single institution prospectively collected database of cartilage procedures was queried for procedures performed between 2000 and 2018. Failure was defined as revision cartilage surgery and/or knee arthroplasty. One hundred and one preoperative and intraoperative features were evaluated as potential predictors. The dataset was randomly divided into training (70%) and independent testing (30%) sets. Four machine learning algorithms were trained and internally validated. Algorithm performance was assessed using area under curve (AUC) and the Brier score. Local Interpretable Model-agnostic Explanations (LIME) was utilized to assess the optimized algorithm fidelity. Results: A total of 1091 patients who underwent surgical procedures addressing cartilage defects in the knee with a minimum of 2-years of follow-up were included. The mean follow-up was 3.5 ± 2.8 years. The mean age was 40.5 ± 15 years. There were 205 (18.8%) patients who failed at final follow-up. The Random Forest algorithm was found to be the best performing algorithm, with an AUC of 0.765 and a Brier score of 0.135. The 10 most important features for predicting failure following surgical procedures addressing cartilage defects of the knee were: symptom duration, age, body mass index (BMI), lesion grade, total lesion area (sum of all lesion areas), number of previous surgeries, number of lesions in the knee, gender, athletic level, and traumatic etiology. LIME analysis allowed for assessment of the optimized algorithm fidelity, as well as provided a patient-specific comparison for the risk of failure of an individual patient being assigned various types of cartilage procedures. Conclusions: Machine learning algorithms were accurate in predicting the risk of failure following cartilage procedures of the knee, with the most important features being symptom duration, age, BMI, lesion grade, and total lesion area. Machine learning algorithms may be used to compare the risk of failure of specific patient-procedure combinations in the treatment of cartilage defects of the knee. Integrated human and machine learning decision-making may improve patient selection and bring about the new era of patient-tailored evidence-based clinical care. Table 1. Demographic and Clinical Characteristics. Table 2. Prior surgical procudures. Figure 1. Global feature importance plot displaying (in a descending order) the most important predictors of failure following surgical procedures addressing cartilage defects of the knee. Figure 2. A-D. The Corresponding receiver operating characteristic (ROC) curve analysis of the four algorithms. A. Elastic-net penalized linear regression (ENPLR, AUC=0.725); B. Random Forest (AUC=0.765); C. Neural Network (AUC=0.742); D. XG Boost (AUC=0.757).

Patient-Reported Outcome Measurement Information System (PROMIS) was developed as a uniform and generalizable PROM system using item response theory and computer adaptive testing. We aimed to assess the utilization of PROMIS for clinically significant outcomes (CSOs) measurements and provide insights into its use in orthopaedic research. We reviewed PROMIS CSO reports for orthopaedic procedures via PubMed, Cochrane Library, Embase, CINAHL, and Web of Science from inception to 2022, excluding abstracts and missing measurements. Bias was assessed using the Newcastle–Ottawa Scale (NOS) and questionnaire compliance. PROMIS domains, CSO measures, and study populations were described. A meta-analysis compared distribution and anchor-based MCIDs in low-bias (NOS ≥ 7) studies. Overall, 54 publications from 2016 to 2022 were reviewed. PROMIS CSO studies were observational with increasing publication rates. Evidence-level was II in 10/54, bias low in 51/54, and compliance ≥ 86

Purpose: To define clinically significant outcomes (CSO) thresholds for minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient-acceptable symptomatic state (PASS) in patients undergoing superior capsular reconstruction (SCR) with an acellular dermal allograft. We also evaluated patient-specific variables predictive of achieving CSO thresholds. Methods: The American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), Single Assessment Numeric Evaluation (SANE), and subjective Constant-Murley (Constant) scores were collected preoperatively and at the most recent follow up for patients undergoing SCR from 2010 to 2019. A distributionbased approach was used to calculate MCID, and an anchor-based approach was used to calculate SCB and PASS. Logistic regression was used to determine factors associated with CSO achievement. Results: Fifty-eight patients were identified (n = 39 males; n = 19 females) with a mean age of 53.4 +/- 14.1 years at surgery and an average follow-up of 23 months. The MCID, SCB, and PASS were 11.2, 18.02, and 68.82 for ASES, 14.5, 23.13, and 69.9 for SANE, and 3.6, 10, and 18 for Constant, respectively. Subscapularis tear, female sex, and workers compensation (WC) status reduced odds of achieving MCID. Reduced odds of achieving Constant SCB were associated with older age, female sex, and WC status, while concomitant distal clavicle excision during SCR and lower preoperative ASES increased odds of achieving ASES SCB. Reduced odds for achieving ASES PASS were associated with female sex and WC status, while reduced odds for achieving SANE PASS were associated with subscapularis tearing preoperatively. Conclusion: On the basis of calculated values for MCID, SCB, and PASS, subscapularis tearing, WC status, age, and sex are associated with failure to achieve clinically significant outcomes following SCR. Concomitant distal clavicle excision during SCR and lower preoperative ASES was predictive for achievement of MCID and SCB. By defining the thresholds and variables predictive of achieving CSOs following SCR, surgeons may better counsel patients prior to SCR.

Purpose:To identify variables associated with operative duration and intraoperative or perioperative complications after primary anterior cruciate ligament reconstruction (ACLR).Methods:Surgeons who performed a minimum of 20 arthroscopic cases per month were recruited for participation through the Arthroscopy Association of North America from 2011 through 2013. All participants agreed to voluntarily submit data for 6 months of consecutive knee and shoulder arthroscopy cases. Only subjects coded for ACLR were analyzed, whereas revision cases were excluded. ACLRs were subdivided into isolated ACLR, ACLR with minor concomitant procedures, and ACLR with major concomitant procedures. Patient, surgeon, and surgical variables were analyzed for their effect on operative duration and complications.Results:One hundred thirty-five orthopaedic surgeons participated, providing 1,180 primary ACLRs (399 isolated ACLRs, 441 ACLRs plus minor procedures, and 340 ACLRs plus major procedures). Most surgeons were in private practice (72.8%). Most patients were male patients (58.8%), and the mean body mass index (BMI) was 26.2 ± 5.1. The overall mean operative duration was 95.9 ± 42.0 minutes (isolated ACLRs, 88.4 ± 36.8 minutes; ACLRs plus minor concomitant procedures, 90.1 ± 37.6 minutes; and ACLRs plus major concomitant procedures, 118.5 ± 112.4 minutes; P < .001). Patient age was inversely correlated with operative duration (ρ = -0.221, P < .001). Surgical procedures performed in an ambulatory surgery center had a shorter mean operative duration (91.5 ± 40.4 minutes) compared with those performed in a hospital setting (105.0 ± 43.8 minutes, P < .001). There were 22 intraoperative and 47 early postoperative complications, with the most common being deep vein thrombosis (n = 15). Surgical volume (knee arthroscopy cases per month) correlated inversely with operative time (ρ = -0.200, P = .001) and complication rate (ρ = -0.112, P < .001). Patient BMI was associated with increased odds of early postoperative complications on multivariate analysis (odds ratio, 1.060; P = .044; 95% confidence interval, 1.002-1.121).Conclusions:Increasing patient age, private practice, ambulatory surgery center setting, and surgeon experience are associated with a shorter operative duration for ACLR. Although an increasing number of arthroscopic knee procedures performed by surgeons correlated with fewer complications, only increasing patient BMI significantly predicted odds of complications.Level of Evidence:Level IV, prognostic case series.

Background: The average professional soccer team experiences 1 to 2 traumatic leg fractures per season, with unknown effects on player performance. Purpose: To (1) determine the rate and time to return to play (RTP) following leg fracture, (2) investigate the rate of reinjury following RTP, and (3) investigate long-term effects that lower extremity (LE) fracture may have on elite soccer player performance. Study Design: Cohort study; Level of evidence, 3. Methods: Using publicly available records, we identified athletes sustaining a traumatic leg fracture across the 5 major European soccer leagues (English Premier League, Bundesliga, La Liga, Ligue 1, and Serie A) between 2000 and 2016. Athletes with leg fracture (femur, tibia, and/or fibula) were matched 1:2 to controls by demographic characteristics and performance metrics 1 season before the index timepoint. Investigations included the RTP rate, reinjury rate, player characteristics associated with RTP within 2 seasons, long-term player retention, performance metrics during the 4 following seasons, and subgroup analysis by player position. Results: A total of 112 players with LE fracture and 224 controls were identified. Players with LE fractures were absent for a mean of 157 days (range, 24-601 days) and 21 games (range, 2-68 games). The rate of RTP within 1 season was 80%, with 4% experiencing subsequent refracture. Injured players remained active in the league at a higher rate than their uninjured counterparts. As compared with controls, injured athletes played 309 fewer total minutes (P < .05), scored 0.09 more assists per game (P < .01) 1 season after injury, and scored 0.12 more points per game 4 seasons after injury (P < .01). Defenders were most affected by an LE fracture, playing 5.24 fewer games (P < .05), 603 fewer total minutes (P < .01), and recording 0.19 more assists per 90 minutes of play as compared with controls 1 season after injury (P < .001). Attackers and midfielders demonstrated no significant difference in metrics after RTP when compared with controls. Conclusion: Most players sustaining an LE fracture returned to elite soccer at the same level after a significant loss of playing time, with a 4% rate of refracture. Player retention was higher for those sustaining an LE fracture versus uninjured controls. Overall, injured players did not experience a decline in performance after recovery from an LE fracture.

Background: The effects of adductor muscle injury on performance in soccer athletes are unknown. Purpose: To (1) determine the rate and time to return to play (RTP) after adductor muscle injury, (2) investigate the rate of reinjury after RTP, and (3) investigate any long-term effects of injury on elite soccer player performance. Study Design: Cohort study; Level of evidence, 3. Methods: Using publicly available records, athletes sustaining adductor muscle injury were identified across the 5 major European soccer leagues (English Premier League, Bundesliga, La Liga, Ligue 1, and Serie A) between 2000 and 2015. Injured athletes were matched to controls by demographic characteristics and performance metrics from 1 season before the index timepoint. Investigations included the rate of RTP, reinjuries, player characteristics associated with RTP within 2 seasons, player availability, field time, and performance metrics during the 4 seasons after injury. Results: A total of 671 players with adductor muscle injury were included. Based on time to RTP, 86% of injuries were mild to moderate (4-28 days missed), and 4% required surgical intervention. Players with adductor muscle injury were absent for a median of 22 days (range, 1-700 days) and 4 games (range, 1-76 games). A total of 521 (78%) players returned at the same level, with no demographic or clinical characteristics associated with RTP on the multivariable regression. Of those returning to play, 143 (21%) experienced adductor reinjury. After RTP, defenders demonstrated decreased field time compared with controls (P < .05). As compared with controls, defenders and midfielders scored more points and goals per game during the season of the injury (P < .01), while attackers recorded more goals and assists per game the season after injury (P < .05). Conclusion: Only 3 in 4 players (78%) returned to participate in an official match, and the reinjury rate was high (21%). After RTP, defenders demonstrated decreased field time versus controls. On the other hand, defenders and midfielders recorded more points and goals per game, while attackers recorded more goals and assists per game versus controls. Although the multivariable analysis results did not identify player characteristics associated with RTP, there was a position-dependent association on player performance after RTP.

Introduction: The threshold values needed to achieve MCID and PASS following HTO with or without concomitant procedures are not well known. Objectives: To determine values and variables predictive for achieving the minimally clinically important difference (MCID) and patient acceptable symptom state (PASS) of patient-reported outcome (PRO) scores following high tibial osteotomy (HTO) with or without associated restoration procedures for the correction of varus deformity. Methods: A prospectively collected HTO outcomes registry was retrospectively reviewed for patients who underwent HTO between 2001 and 2018. Collected PROs included International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Lysholm scores. A distribution-based approach was used to calculate MCID, and an anchor-based approach was used for the calculation of PASS. Results: Fifty-five patients were identified (n = 43 males; n = 12 females) with a mean age of 37.9 ± 9.0 years at surgery and average follow-up of 3.3 ± 3.1 years. The MCID and PASS for IKDC were calculated as 12.5 and 40.23, respectively. MCID and PASS values for each of the KOOS subscales were as follows: symptoms: 9.9 and 71.43; pain: 11.3 and 72.22; daily living: 12.0 and 77.94; sports: 16.0 and 40; quality of life: 15.1 and 56.25, respectively. Conclusions: Based on calculated values for MCID and PASS following HTO using IKDC and KOOS subscales, higher preoperative PROs, prior medial meniscectomy, higher BMI, concomitant ACL reconstruction and worker's compensation status were associated with failure to achieve clinically significant outcomes. Prior ACL reconstruction was found to be predictive of MCID for KOOS-symptoms.

Introduction The influence of patient demographic factors in predicting the success and failure of HTO remains largely unknown. Objectives To determine factors associated with success or failure after high tibial osteotomy (HTO) for unicompartmental knee pain with varus deformity at a minimum of 2-year follow-up. Methods A prospectively collected HTO outcomes registry was queried for patients undergoing HTO. Demographic, preoperative, intraoperative, radiographic, and postoperative data were collected. Patient factors were analyzed for their association with HTO failure, which was defined as conversion to uni- or total knee arthroplasty. Results Seventy-five patients were identified (n = 58 males; n = 17 females) with a mean age of 37.3 ± 8.7 years at surgery and average follow-up of 5.5 ± 3.8 years. Forty-eight percent (n = 36) of patients underwent reoperation, 28% (n = 21) underwent hardware removal, and 17% (n = 13) converted to arthroplasty. Increased body mass index (BMI) (> 30 kg/m2) (P = .025) and age > 45 years (P = .020) were associated with HTO failure, while performance of concomitant procedures decreased failure probabilities (P = .008). Conclusion s: High tibial osteotomy is an effective procedure for symptomatic patients with varus deformity, associated with a significant improvement in PROs, a moderate complication rate, and a high survival rate. Reoperation rates remain common, while failure rates requiring conversion to arthroplasty necessitate HTO be performed in appropriately selected patients. Performance of concomitant joint preservation procedures at the time of HTO was protective against HTO failure, while greater patient age and BMI were associated with HTO failures. Level of Evidence Level 4, Case series

PURPOSE:To analyze the effect of patient age, sex, and associated preoperative factors on patient-reported outcome (PRO) measures and graft survival following primary meniscal allograft transplantation (MAT). METHODS:A prospectively collected database was retrospectively reviewed to identify patients who underwent primary MAT with a minimum of 2 years of follow up between 1999 and 2017. Demographic, intraoperative, and postoperative outcome data were collected for each patient. Postoperative outcomes were stratified based on age and sex, and comparative statistical analysis was performed between sexes, both >40 and <40. RESULTS:A total of 238 patients underwent primary MAT during the study period, of which 212 patients (mean age, 28.5 ± 9.0 years; range, 15.01-53.67 years) met the inclusion criteria with a mean follow-up of 5.1 ± 3.4 years (range 2.0-15.9 years). At final follow-up, patients ≥40 and <40 years of age demonstrated statistically significant improvements in nearly all PRO scores (P < .05 for both groups). There were no significant differences between either group for achievement of minimal clinically important difference for International Knee Documentation Committee (P = .48) or Knee Injury and Osteoarthritis Outcome Score symptoms (P = .76). Because of insufficient numbers, a statistically significant difference could not be demonstrated in reoperation rate (≥40: 1.49 ± 1.77 years, <40: 1.87 ± 1.98 years, P = .591), failure rate (≥40: 7/32 [21.9%], <40: 19/180 [10.6%], P = .072), or complication rate (≥40: 2/32 [6.3%], <40: 12/180 [6.7%], P = .930) based on age. Both sexes showed a significant improvement in PROs, whereas female patients were more likely to undergo revision surgery (P = .033), with no significant differences based on time to reoperation, failure, or complication rates. CONCLUSIONS:PROs similarly improved following MAT in both patients aged ≥40 and those <40 at final follow-up with no significant differences in minimal clinically important difference achievement rate, complication rate, reoperation rate, time to reoperation, or failure rate between groups. Female patients may be more likely to undergo revision surgery after MAT. LEVEL OF EVIDENCE:III; therapeutic retrospective comparison study.

PURPOSE:Comparing symptoms of patients with focal cartilage defects of the knee to those with knee osteoarthritis.METHODS:Prospectively maintained databases identified patients with focal cartilage defects (FCD group) who underwent osteochondral allograft transplantation and patients with osteoarthritis (OA group) undergoing arthroplasty. Patients between 18 and 55 years of age were included and matched based on age. Baseline patient demographics, symptoms, and patient-reported outcomes including the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR), SF-12, and VR-12 questionnaires were recorded. Patient symptoms and individual responses of the KOOS JR were compared between groups. Regression analysis was used to evaluate the association between pre-operative factors that significantly differed between groups and the KOOS JR questionnaire.RESULTS:Sixty-four patients were included: 32 patients in each group. The FCD group had a significantly lower body mass index (BMI) (p = 0.04) and greater number of workers' compensation cases (p = 0.027) when compared to the OA group. Patients in the OA group complained more frequently of medial-sided pain (p = 0.02) and knee swelling (p = 0.003). The OA cohort also had greater pain with fully straightening the knee (p = 0.012), pain with standing upright (p = 0.016), and pain with rising from sitting (p = 0.003). Patients in the FCD group had greater KOOS JR outcome scores (51.5 ± 12.9 vs. 41.5 ± 20.5; p = 0.023).CONCLUSION:When compared to patients with focal cartilage defects, adults with knee osteoarthritis scheduled for knee arthroplasty have a more severe presentation of symptoms, particularly medial-sided pain, swelling of the knee, pain associated with straightening the knee, standing upright, and rising from sitting.

Category: Ankle; Ankle Arthritis; Trauma Introduction/Purpose: Tibiotalocalcaneal (TTC) arthrodesis is a routinely utilized salvage procedure that treats patients with severe talar and subtalar joint disease. Unfortunately, nonunion is a relatively common complication postoperatively which can increase risks and costs for patients. The goal of this study is to review the literature to identify risk factors for nonunion post TTC arthrodesis and stratify them based on strength of evidence. A meta-analysis will be performed on risk factors when appropriate to establish values based on pre-existing studies. Methods: Five databases (CINAHL, Cochrane Library, EMBASE, MEDLINE, and Web of Science) were searched from inception to May 17th, 2020. Two independent reviewers screened abstracts and full-text articles for those that included risk factors predictive of nonunion for TTC arthrodesis. Any disagreements were discussed between the two reviewers and a third reviewer served as the ultimate decision maker if a consensus could not be reached. Relevant data regarding participants’ characteristics, study design, follow-up time, statistical tests and identified risk factors were extracted from the included studies. The two reviewers independently appraised the methodological quality of the studies using the Quality In Prognosis Studies tool. Those risk factors described in multiple studies were included in the meta-analysis. Random effects meta-analyses were summarized as forest plots of individual study and pooled random effect results. Results were reported as odds ratios (OR) with 95% confidence intervals (CI). Results: Database search identified 428 articles, of which 113 were screened for full text. Eight studies involving 607 patients were included and 33 potential risk factors for nonunion were identified. Risk factors were stratified into demographic, preoperative, intraoperative and postoperative. Results of the meta-analysis established two significant risk factors for nonunion following TTC arthrodesis. Strong evidence supports that prior neurological deficits, such as Charcot neuroarthropathy and diabetes neuropathy, are associated with nonunion following surgery (OR: 2.86, 95% CI: 1.56 - 5.23). There was moderate evidence to suggest that preoperative infection was predictive for nonunion (OR: 3.99, 95% CI: 1.26 - 12.68). Although our meta- analysis did not find smoking (OR: 1.75, 95% CI: 0.90 - 3.38) or diabetes (OR: 2.28, 95% CI: 0.98 - 5.34) to be significant risk factors, multiple high quality studies support these as comorbidities that increase the likelihood of nonunion. Conclusion: TTC arthrodesis can be an effective salvage procedure but is associated with high nonunion rates. The results of our meta-analysis suggest that prior neurological deficits, such as Charcot neuroarthropathy or diabetes neuropathy, have strong evidence for failure to achieve union. Although our meta-analysis did not find other statistically significant risk factors, the findings of individual studies in our review suggest that diabetes mellitus and smoking are both factors which can lead to failure of fusion. Surgeons should be cognizant of these risks when performing TTC arthrodesis and carefully monitor patients with the aforementioned comorbidities to achieve successful results.

BACKGROUND:Osteochondral allograft (OCA) transplant for symptomatic focal cartilage defects in the knee has demonstrated favorable short- to midterm outcomes. However, the reoperation rate is high, and literature on mid- to long-term outcomes is limited.PURPOSE:To analyze clinically significant outcomes (CSOs), failures, and graft survival rates after OCA transplant of the femoral condyles at a minimum 5-year follow-up.STUDY DESIGN:Case series; Level of evidence, 4.METHODS:Review of a prospectively maintained database of 205 consecutive patients who had primary OCA transplant was performed to identify patients with a minimum of 5 years of follow-up. Outcomes including patient-reported outcomes (PROs), CSOs, complications, reoperation rate, and failures were evaluated. Failure was defined as revision cartilage procedure, conversion to knee arthroplasty, or macroscopic graft failure confirmed using second-look arthroscopy. Patient preoperative and surgical factors were assessed for their association with outcomes.RESULTS:A total of 160 patients (78.0% follow-up) underwent OCA transplant with a mean follow-up of 7.7 ± 2.7 years (range, 5.0-16.3 years). Mean age at the time of surgery was 31.9 ± 10.7 years, with a mean symptom duration of 5.8 ± 6.3 years. All mean PRO scores significantly improved, with 75.0% of patients achieving minimal clinically important difference (MCID), and 58.9% of patients achieving significant clinical benefit for the International Knee Documentation Committee score at final follow-up. The reoperation rate was 39.4% and was associated with a lower probability of achieving MCID. However, most patients undergoing reoperation did not proceed to failure at final follow-up (63.4% of total reoperations). A total of 34 (21.3%) patients had failures overall, and the 5- and 10-year survival rates were 86.2% and 81.8%, respectively. Failure was independently associated with greater body mass index, longer symptom duration, number of previous procedures, and previous failed cartilage debridement. Athletes were protected against failure. Survival rates over time were not affected by OCA site (P = .154), previous cartilage or meniscal procedure (P = .287 and P = .284, respectively), or concomitant procedures at the time of OCA transplant (P = .140).CONCLUSION:OCA transplant was associated with significant clinical improvement and durability at mid- to long-term follow-up, with 5- and 10-year survival rates of 86.2% and 81.8%, respectively. Maintenance of CSOs can be expected in the majority of patients at a mean of 7.7 years after OCA transplant. Although the reoperation rate was high (39.4%) and could have adversely affected chances of maintaining MCID, most patients did not have failure at long-term follow-up.

The demand of low power high density integrated circuits is increasing in modern battery operated portable systems. Sub-threshold region of MOS transistors is the most desirable region for energy efficient circuit design. The operating ultra-low power supply voltage is the key design constraint with accurate output performance in sub-threshold region. Degrading of the performance metrics in Static random access memory (SRAM) cell with process variation effects are of major concern in sub-threshold region. In this paper, a bootstrapped driver circuit and a bootstrapped driver dynamic body biasing technique is proposed to assist write operation which improves the write-ability of sub-threshold 8T-SRAM cell under process variations. The bootstrapped driver circuit minimizes the write delay of SRAM cell. The bootstrapped driver dynamic body bias increases the output voltage levels by boosting factor therefore increasing in switching threshold voltage of MOS devices during hold and read operation of SRAM latch. The increment in threshold voltage improves the static noise margin and minimizing the process variation effects. Monte-Carlo simulation results with 3\(\sigma \) Gaussian distributions show the improvements in write delay by 11.25 %, read SNM by 12.20 % and write SNM by 12.57 % in 8T-SRAM cell under process variations at 32 nm bulk CMOS process technology node.