Parkes, Chad W.

Objective Subchondral insufficiency fracture of the knee (SIFK) is associated with high rates of osteoarthritis (OA) and arthroplasty. The implantable shock absorber (ISA) is an extra-capsular implant that unloads the medial knee compartment. This study compared the 2-year freedom from arthroplasty rates in subjects with medial knee OA and SIFK when treated with an ISA versus a matched cohort of patients treated non-surgically. Design This retrospective case-control study compared 2-year conversion rates to arthroplasty in SIFK score-, age-, and body mass index (BMI)–matched control subjects without prior surgical history with ISA-implanted subjects from an ongoing prospective study. Baseline and final radiographs, and MRIs were reviewed for evaluation of meniscus or ligament injuries, insufficiency fractures, and subchondral edema. Kaplan-Meier analysis assessed survival. Results Forty-two patients (21 Control: 21 ISA), mean age = 52.3 ± 8.7 years, BMI = 29.5 ± 3.9 kg/m 2 , 40% female were evaluated. Both ISA and Control arms had the same numbers of low ( n = 4), medium ( n = 11), and high-risk ( n = 6) SIFK scores. One- and 2-year freedom-from-arthroplasty rates were both 100% for ISA subjects, and 76% and 55%, respectively, for Controls ( P = 0.001 for cross-group comparison). Control knees with low, medium, and high-risk SIFK scores had respective 1- and 2-year survival rates of 100% and 100%, 90% and 68% ( P = 0.07 vs. ISA), and 33% and 0% ( P = 0.002 vs. ISA). Conclusions ISA intervention was strongly associated with avoidance of arthroplasty at a minimum 2 years, especially in patients with high-risk SIFK scores. SIFK severity scoring predicted relative risk of conversion to arthroplasty through at least 2 years in non-surgically treated subjects.

AbstractSubchondral insufficiency fractures of the knee (SIFK) can result in high rates of osteoarthritis and arthroplasty. The implantable shock absorber (ISA) implant is a titanium and polycarbonate urethane device which reduces the load on the medial compartment of the knee by acting as an extra-articular load absorber while preserving the joint itself. The purpose of this study was to evaluate whether partially unloading the knee with the ISA altered the likelihood of progression to arthroplasty utilizing a validated predictive risk model (SIFK score). A retrospective case-control (2:1) study was performed on patients with SIFK without any previous surgery and on those implanted with the ISA with the primary outcome being progression to arthroplasty compared with nonoperative treatment at 2 years. Baseline and final radiographs, as well as magnetic resonance imagings, were reviewed for the evaluation of meniscus or ligament injuries, insufficiency fractures, and subchondral edema. Patients from a prospective study were matched using the exact SIFK Score, a validated predictive score for progression to arthroplasty in patients with SIFK, to those who received the ISA implant. Kaplan–Meier analysis was conducted to assess survival. A total of 57 patients (38 controls:19 ISA) with a mean age of 60.6 years and 54% female were included. The SIFK score was matched exactly between cases and controls for all patients. The 2-year survival rate of 100% for the ISA group was significantly higher than the corresponding rate of 61% for the control group (p < 0.01). In ISA, 0% of the patients converted to arthroplasty at 2 years, and 5% (one patient) had hardware removal at 1 year. When stratified by risk, the ISA group did not have a significantly higher survival compared with low-risk (p = 0.3) or medium-risk (p = 0.2) controls, though it had a significantly higher survival for high-risk groups at 2 years (100 vs. 15%, p < 0.01). SIFK of the medial knee can lead to significant functional limitation and high rates of conversion to arthroplasty. Implants such as the ISA have the potential to alter the progression to arthroplasty in these patients, especially those at high risk.

Background: Basic pitcher statistics have been used to assess performance in pitchers after injury or surgery without being validated. Even among healthy pitchers, the normal variability of these parameters has not yet been established. Purpose: To determine (1) the normal variability of basic and advanced pitcher statistics in healthy professional baseball pitchers and (2) the minimum pitches needed to predict these parameters. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Publicly available data from the MLB Statcast and PITCHf/x databases were used to analyze MLB pitchers during the 2015 and 2016 seasons who recorded a minimum of 100 innings without injury. Basic and advanced baseball pitcher statistics were analyzed. The variability of each parameter was assessed by computing the coefficient of variation (CV) between individual pitchers and across all pitchers. A CV <10 was indicative of a relatively constant parameter, and parameters with a CV >10 were generally considered inconsistent and unreliable. The minimum number of pitches needed to be followed for each variable was also analyzed. Results: A total of 118 pitchers, 55 baseball-specific statistical metrics (38 basic and 17 advanced), and 7.5 million pitches were included and analyzed. Of the 38 basic pitcher statistics, only fastball velocity demonstrated a CV <10 (CV = 1.5), while 6 of 17 (35%) advanced metrics demonstrated acceptable consistency (CV <10). Release position from plate and velocity from the plate were the 2 most consistent advanced parameters. When separated by pitch type, these 2 parameters were the most constant (lowest CV) across every pitch type. Conclusion: We recommend against utilizing nonvalidated statistical measures to assess performance after injury, as they demonstrated unacceptably high variability even among healthy, noninjured professional baseball pitchers. It is our hope that this study will serve as the foundation for the identification and implementation of validated pitcher-dependent statistical measures that can be used to assess return-to-play performance after injury in the future.

Purpose To evaluate both the potential causes and resultant outcomes in patients in whom subchondral insufficiency fracture of the knee (SIFK) develops after arthroscopy. Methods We performed a retrospective review of all patients with a magnetic resonance imaging diagnosis of SIFK after arthroscopic meniscectomy and chondroplasty over a 12‐year period. Results A total of 28 patients were included, with a mean age of 61 years and mean follow‐up period of 5.7 years. SIFK showed a predilection for the medial compartment (n = 25, 89%), specifically the medial femoral condyle (n = 21, 75%). In 7 patients (25%), SIFK developed in both the femoral condyle and tibial plateau in the ipsilateral compartment. Fifteen patients (54%) went on to conversion to arthroplasty at a mean of 0.72 years. The rate of survival free of conversion to arthroplasty was 57%, 45%, and 40% at 1 year, 2 years, and 5 years, respectively. Furthermore, 63% of patients with a meniscal tear and SIFK in the same compartment went on to arthroplasty ( P = .04). There was an increased risk of conversion to arthroplasty if SIFK was present in both the femur and tibia in the same compartment ( P = .04). A higher Kellgren‐Lawrence grade at the time of the SIFK diagnosis increased the likelihood of eventual arthroplasty ( P = .03). The presence of SIFK in both the femur and tibia in the ipsilateral compartment, an increased Kellgren‐Lawrence grade, and a meniscal tear or prior meniscectomy in the same compartment as SIFK were associated with an increased risk of eventual arthroplasty. Conclusions Post‐arthroscopic SIFK most commonly occurs in the medial compartment, particularly in patients who underwent a prior meniscectomy. The presence of meniscal root and radial tears in these patients is notable (75%). Ultimately, there is a high rate of progression of arthrosis (33%) and eventual conversion to arthroplasty. Level of Evidence Level IV, case series.

Purpose To report the annual incidence of anterior shoulder instability (ASI) diagnosis, injury severity, and surgical stabilization in a U.S. population. Methods An established U.S. geographic database was used to identify patients < 40 years old with diagnoses of ASI from 1994‐2016. Medical records were reviewed to obtain patient demographics, histories, imaging results, and surgical details. Age‐ and sex‐specific incidence rates were calculated and adjusted to the 2010 U.S. population. Poisson regression was performed to examine trends by timeline, sex and age. Results The study population consisted of 652 patients with ASI and a mean age of 21.5 years (range, 3.6‐39.5). Comparing 2015‐2016 to 1994‐1999, we found an increase in the number of dislocations (from 1.0‐1.9; P = 0.016) and total instability events (from 2.3‐3.4; P = 0.041) per patient prior to presentation to a physician. There was a trend in increased diagnosis of bony Bankart and/or Hill‐Sachs on MRI over time, with these lesions documented in 96% of patients undergoing MRI in 2015‐2018 compared to 52.9% in 1994‐1999 ( P < .001). The use of arthroscopic procedures increased and peaked in 2005‐2009 (90% of surgical cases performed). The proportion of open Latarjet procedures increased from 2010‐2014 (14%) and 2015‐2018 (31%). Conclusions The age‐ and sex‐ adjusted incidence of ASI diagnosis in a U.S. population from 1994‐2016 is comparable to that demonstrated in Canadian and European populations. This study demonstrates an increasing number of instability events prior to surgical evaluation, which may correlate with patients’ more commonly presenting with bone loss and requiring more aggressive surgical treatment or that ASI is being more frequently cared for and documented by present‐day orthopedic surgeons. Level of Evidence Level III, cross‐sectional study.

Purpose To compare the (1) rates of complications and reoperations, (2) rate of anterior cruciate ligament (ACL) graft failure, and (3) patient‐reported outcomes (PROs) among patients after hamstring autograft ACL reconstruction (ACLR) with and without independent suture tape reinforcement at a minimum 2‐year clinical follow‐up. Methods We performed a 1:2 matched‐cohort comparison of patients who underwent hamstring autograft ACLR with and without independent suture tape reinforcement between July 2011 and July 2017. Patients were matched according to age, sex, body mass index, preinjury Tegner activity score, and concomitant meniscal injury. Medical records were reviewed for demographic characteristics, additional injuries, and concomitant procedures. PRO scores (including Tegner activity, Lysholm, and International Knee Documentation Committee scores) and physical examination findings were collected both preoperatively and at a minimum of 2 years postoperatively. Results Overall, 108 patients who underwent ACLR were included: 36 patients (mean age, 25.3 years; range, 13‐44 years) with independent suture tape reinforcement and 72 patients (mean age, 24.9 years; range, 13‐54 years) without suture tape reinforcement. Overall, 5 of 36 suture tape patients (14%) and 10 of 72 control patients (14%) underwent reoperations. At an average follow‐up of 26.1 months in the suture tape cohort and 31.3 months in the control cohort, 1 patient in the suture tape cohort and 4 patients in the control cohort experienced graft failure. There were no statistically significant differences between the suture tape and control groups regarding return‐to‐sport rate (89% and 88%, respectively), postoperative International Knee Documentation Committee score (94.4 and 93.8, respectively), and postoperative Lysholm score (95.6 and 94, respectively). There was a statistically significant difference between the suture tape and control groups in postoperative Tegner activity score, at 7.1 (95% confidence interval, 6.5‐7.6) and 6.4 (95% confidence interval, 6.2‐6.6), respectively ( P = .026). Conclusions ACLR with hamstring autograft and independent suture tape reinforcement was performed safely with low rates of complications, graft failure, and reoperations with similar PROs, function, and return‐to‐sport rates when compared with hamstring autograft ACLR without suture tape reinforcement at a minimum 2‐year follow‐up. Level of Evidence Level III, retrospective comparative study.

AbstractPurposeThe purpose of this study was to evaluate the effect of preoperative patella alta on clinical outcomes, survivorship, and complication and reoperation rates on patellofemoral arthroplasty (PFA).MethodsAll patients who underwent PFA for isolated patellofemoral arthritis by a single surgeon at our institution were identified. Preoperative radiographs were measured by two independent observers for patellar height using the Caton Deschamps (CD), Insall‐Salvati (IS), and Blackburne‐Peele (BP) methods. Patients were classified as either “patella alta” or “non‐patella alta” for all three measurement methods. Clinical scores including KSS Pain, KSS Function, and Tegner Activity Scores were collected pre‐ and post‐operatively. Failure was defined as conversion to total knee arthroplasty (TKA). Clinical outcomes and survivorship were compared between patients with “patella alta” and “non‐patella alta” height measurements.ResultsThere were 119 patients with 153 knees (86% female) included in the study with a mean age of 55.8 years. Outcome scores improved from pre‐operative to post‐operative for both patella alta and non‐patella alta patients for Tegner, KSS pain and KSS function scores. The mean change in Tegner scores for patella alta and non‐patella alta patients were not significantly different for CD (p = 0.24), IS (p = 0.25) or BP measurements (p = 0.39). The mean change in KSS pain scores between groups were not significantly different for CD (p = 0.33) or IS measurements (p = 0.22), but was improved more significantly in patella alta patients vs non‐patella alta patients (21.2 and 14.4; p = 0.02) for BP measurement. The mean change in KSS function scores between groups was not significantly different for CD (p = 0.61) IS (p = 0.90) or BP measurements (p = 0.79). The overall survivorship from conversion to total knee arthroplasty (TKA) was 94.1% at a mean follow‐up time of 5.0 (SD 2.6) years. There were no significant differences in survivorship from TKA between patella alta and non‐patella alta groups (CD: p = 0.72, IS: p = 0.63, BP: p = 0.66).ConclusionsThis study suggests that there are no significant differences in clinical outcome scores or survivorship from TKA between patella alta and non‐patella alta patients who underwent onlay design PFA. Both patella alta and non‐patella alta patients demonstrated excellent improvement in outcome scores from pre‐operative to post‐operative.Level of evidenceIV.

Background: Spontaneous osteonecrosis of the knee has recently been termed subchondral insufficiency fracture of the knee (SIFK) to appropriately recognize the etiology of mechanical overloading of the subchondral bone. The purpose of this study was to assess clinical outcomes of SIFK based on progression to surgical treatment and arthroplasty, and to evaluate the risk factors that increase the progression to arthroplasty. Methods: A retrospective review was performed on patients with a diagnosis of SIFK, as confirmed with use of magnetic resonance images (MRIs). Baseline and final radiographs were reviewed. Baseline MRIs were also reviewed for injury characteristics. Failure was defined as progression to surgical treatment or conversion to arthroplasty. Results: Two hundred twenty-three patients (71% female) with a mean age of 65.1 years were included. SIFK affected 154 femora (69%) and 123 tibiae (55%), with medial compartment involvement in 198 knees (89%); 74% of medial menisci had root or radial tears, with a mean extrusion of 3.6 mm. Varus malalignment was identified in 54 (69%) of 78 knees. Seventy-six (34%) of all patients progressed to surgical intervention at 2.7 years, and 66 (30%) underwent arthroplasty at 3.0 years. The rates of conversion to surgical intervention and arthroplasty increased to 47% (37 of 79; p = 0.04) and 37% (29 of 79; p = 0.09), respectively, in patients with >5 years of follow-up. The 10-year survival rate free of arthroplasty for patients with SIFK on the medial femoral condyle (p < 0.01), SIFK on the medial tibial plateau (p < 0.01), medial meniscal extrusion (p = 0.01), varus alignment (p = 0.02), and older age (per year older; p = 0.003) was significantly higher than the survival rates of those without each respective condition. Conclusions: Subchondral insufficiency fractures predominantly involve the medial compartment of the knee and commonly present with medial meniscal root and radial tears. Approximately one-third of patients progressed to total knee arthroplasty. Baseline arthritis, older age, location of the insufficiency fracture on both the medial femoral condyle and medial tibial plateau, meniscal extrusion, and varus malalignment were all associated with progression to arthroplasty. Level of Evidence: Prognostic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Objectives: Traditional pitching statistics (ERA, WHIP, etc) have been used as surrogates for pitcher performance without being validated. Even amongst healthy pitchers, the normal variability of these parameters has not yet been established. The purpose of this study was to determine the normal variability of basic and advanced pitching statistics in non-injured Major League Baseball (MLB) pitchers. It is our hope that this work will serve as the foundation for the identification and implementation of validated, pitcher dependent statistical measures that can be used to assess return to play performance following injury. Methods: Publicly available data from MLB Statcast and Pitch/Fx databases was used to analyze all non-injured MLB pitchers during 2015 and 2016 seasons who pitcher greater than 100 innings each season without injury. Traditional and advanced baseball pitching statistics were analyzed. The variability of each parameter was assessed by computing coefficient of variation (CV) between individual pitchers and across all pitchers. A CV below 10 is typically indicative of a relatively constant parameter, and parameters with a CV > 10 are generally considered inconsistent and unreliable. Results: A total of 118 pitchers met all inclusion criteria. For each of these healthy pitchers, 38 basic/traditional parameters and 17 advanced parameters were analyzed. Of the traditional pitcher statistics, only 1 (3%) demonstrated a CV value < 10 (average fastball velocity [FBv]; CV 1.5) (Figure 1). In advanced statistics, 9 of 17 (53%) variables demonstrated acceptable consistency as evidenced by a CV value < 10 (Figure 2). Release position from plate (release_pos_y) along with velocity from the plate (vy0) where the two most constant advanced parameters. When separated by pitch type, these two parameters were the most constant (lowest CV) in every pitch type. Conclusion: The validity and variability of baseball statistics as surrogate markers for performance after injury/surgery have not yet been evaluated. It is critical that baseball statistics undergo proper vetting prior to being used to assess recovery. This study reveals average fastball velocity and release position from the plate to be the least variable basic and advanced baseball statistics in MLB pitchers. In total, only 10 of the 55 statistics analyzed demonstrated acceptable consistency and reliability. This study can be further used to determine the minimum time that each of these variables needs to be followed to ensure an appropriate sample size is obtained to detect significant differences in pre- and post- injury performance. [Figure: see text][Figure: see text]

Purpose To compare patellar bone socket and cortical surface fixation techniques for isolated medial patellofemoral ligament (MPFL) reconstruction and determine whether there was a difference in (1) complication rates, including fracture of the patella; (2) redislocation rates; or (3) patient‐reported outcomes. Methods A literature search was conducted following Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines. We included patients who underwent isolated MPFL reconstruction for recurrent patellar instability. Patients with confirmed concomitant or prior ipsilateral knee procedures, multiligament injury, or less than 3 months of follow‐up were excluded. Risk‐of‐bias assessment was performed using the Methodological Index for Non‐randomized Studies (MINORS) system. Studies were classified by surgical technique (patellar bone socket group [group S] vs cortical fixation group [group F]), and complications, redislocations, and patient‐reported outcomes were collected. Results A total of 29 studies yielded 981 patients with MPFL reconstruction for inclusion. Of the patients, 620 underwent a patellar bone socket technique and 361 underwent a cortical fixation technique. Patients ranged in age from 11 to 68 years. Patellar fracture rates ranged from 0% to 17% in group S and were 0% in all group F studies. Mean Kujala scores ranged from 83.5 to 93.6 in group S and from 84.4 to 94.5 in group F. Mean Lysholm scores ranged from 84.6 to 91.7 in group S and from 83.5 to 95 in group F. Redislocation rates ranged from 0% to 21% in group S and from 0% to 13% in group F. Although heterogeneous in nature, complication rates ranged from 0% to 28% in group S and from 0% to 4% in group F. Conclusions MPFL reconstruction techniques with patellar bone sockets showed a larger range of complication rates than cortical fixation techniques, although overall, complications remained uncommon. Clinically, the bone socket group had comparable postoperative redislocation rates and patient outcomes to the group treated with cortical fixation techniques. Level of Evidence Level IV, systematic review of Level I through IV studies.