Predictive modeling of ambulatory outcomes after spinal cord injury using machine learning.

STUDY DESIGN: Retrospective multi-site cohort study. OBJECTIVES: To develop an accurate machine learning predictive model using predictor variables from the acute rehabilitation period to determine ambulatory status in spinal cord injury (SCI) one year post injury. SETTING: Model SCI System (SCIMS) database between January 2000 and May 2019. METHODS: Retrospective cohort study using data that were previously collected as part of the SCI Model System (SCIMS) database. A total of 4523 patients were analyzed comparing traditional models (van Middendorp and Hicks) compared to machine learning algorithms including Elastic Net Penalized Logistic Regression (ENPLR), Gradient Boosted Machine (GBM), and Artificial Neural Networks (ANN). RESULTS: Compared with GBM and ANN, ENPLR was determined to be the preferred model based on predictive accuracy metrics, calibration, and variable selection. The primary metric to judge discrimination was the area under the receiver operating characteristic curve (AUC). When compared to the van Middendorp all patients (0.916), ASIA A and D (0.951) and ASIA B and C (0.775) and Hicks all patients (0.89), ASIA A and D (0.934) and ASIA B and C (0.775), ENPLR demonstrated improved AUC for all patients (0.931), ASIA A and D (0.965) ASIA B and C (0.803). CONCLUSIONS: Utilizing artificial intelligence and machine learning methods are feasible for accurately classifying outcomes in SCI and may provide improved sensitivity in identifying which individuals are less likely to ambulate and may benefit from augmentative strategies, such as neuromodulation. Future directions should include the use of additional variables to further refine these models.

Preoperative patient factors that predict achieving the minimal clinically important difference following arthroscopic treatment of snapping scapula syndrome.

BACKGROUND: The aim of this study was to define the minimal clinically important difference (MCID) values for patient-reported outcomes (PROs) after arthroscopic treatment of snapping scapula syndrome (SSS) using a distribution-based method, and to identify demographic, clinical, and intraoperative factors significantly associated with the achievement of MCID. It was hypothesized that subjective satisfaction scores after the procedure would be strongly associated with the achievement of MCID thresholds for the PROs and that pain, preoperative response to injection, and a scapulectomy in addition to bursal resection would be predictive of clinically relevant improvement. METHODS: Patients who underwent arthroscopic treatment of SSS between October 2005 and September 2020 with a minimum of 2-year short-term postoperative follow-up were enrolled in this retrospective single-center study. The MCID was calculated using a distribution-based approach for the following PROs: 12-Item Short Form Health Survey (SF-12), American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), Quick Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH), Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) pain "today" and "at worst." The association between achievement of the MCID and postoperative subjective satisfaction was investigated, and factors associated with achievement of MCID were determined using bivariate analysis. RESULTS: Of a total of 190 patients assessed for eligibility, 77 patients (38.1 ± 14.3 years; 36 females) were included. Within the study population, statistically significant improvements in postoperative SF-12 physical component summary (PCS) (P < .001) and mental component summary (MCS) (P < 0.034), ASES (P < .001), QuickDASH (P < .001), SANE (P < .001), and VAS pain (P < .001) scores were observed at the minimum 2-year follow-up. The calculated MCID threshold values based on the study population were 5.0 for SF-12 PCS, 5.8 for SF-12 MCS, 11.3 for ASES, -10.5 for QuickDASH, 14.7 for SANE, 1.5 for VAS pain, and 1.7 for VAS pain at worst. Reaching the MCID was strongly associated with postoperative satisfaction (rated on a scale of 1-10). Across the PROs, younger age, favorable preoperative response to injection, partial scapuloplasty or scapulectomy, no prior surgery, and pain and function at baseline were significantly associated with attaining MCID. CONCLUSIONS: Patients who underwent arthroscopic treatment for SSS experienced clinically significant improvements in functional scores, pain, and quality of life. This study demonstrated predictive roles for certain patient-specific factors and diagnostic variables for achieving MCID in PROs, which may help surgeons preoperatively assess the probability of success and manage patient expectations.

Platelet-Rich Plasma, Bone Marrow Aspirate Concentrate, and Hyaluronic Acid Injections Outperform Corticosteroids in Pain and Function Scores at a Minimum of 6 Months as Intra-Articular Injections for Knee Osteoarthritis: A Systematic Review and Network Meta-analysis.

PURPOSE: To compare the efficacy of common intra-articular injections used in the treatment of knee osteoarthritis, including corticosteroid (CS), hyaluronic acid (HA), platelet-rich plasma (PRP), and bone marrow aspirate concentrate (BMAC), with a minimum follow-up of 6-months. METHODS: A literature search was conducted using the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in August 2022 in the following databases: PubMed/MEDLINE, Scopus, Cochrane Database of Controlled Trials, and the Cochrane Database of Systematic Reviews. Level I to II randomized clinical trials with a minimum follow-up of 6 months that investigated the treatments of interest were included. Patient-reported outcome scores for pain and function at baseline and at latest follow-up were extracted, and the change in scores was converted to uniform 0 to 100 scales. Arm-based Bayesian network meta-analysis using a random-effects model was created to compare the treatment arms in pain and function. RESULTS: Forty-eight studies comprising a total of 9,338 knees were included. The most studied intra-articular injection was HA (40.9%), followed by placebo (26.2%), PRP (21.5%), CS (8.8%), and then BMAC (2.5%). HA and PRP both led to a significant improvement in pain compared with placebo. HA, PRP, and BMAC all led to a significant improvement in function scores when compared with placebo. Surface under the cumulative ranking curves (SUCRAs) of the interventions revealed that PRP, BMAC, and HA were the treatments with the highest likelihood of improvement in both pain and function, with overall SUCRA scores of 91.54, 76.46, and 53.12, respectively. The overall SUCRA scores for CS and placebo were 15.18 and 13.70, respectively. CONCLUSIONS: At a minimum 6-month follow-up, PRP demonstrated significantly improved pain and function for patients with knee osteoarthritis compared with placebo. Additionally, PRP exhibited the highest SUCRA values for these outcomes when compared with BMAC, HA, and CS. LEVEL OF EVIDENCE: Level II, meta-analysis of Level I to II studies.

Improved Functional Outcomes of Combined Hip Arthroscopy and Periacetabular Osteotomy at Minimum 2-Year Follow-Up.

PURPOSE: To evaluate patient-reported outcomes (PROs) and survivorship at minimum 2-year follow-up after combined hip arthroscopy and periacetabular osteotomy (PAO) performed in the setting of a single anesthetic event. METHODS: Patients who underwent combined hip arthroscopy (M.J.P.) and PAO (J.M.M.) between January 2017 and June 2020 were identified. Preoperative and minimum 2-year postoperative PROs including Hip Outcome Score-Activities of Daily Living (HOS-ADL), HOS-Sport, modified Harris Hip Score (mHHS), Western Ontario and McMaster Universities Osteoarthritis Index, 12-Item Short Form Survey Mental Component Scores (SF-12 MCS), and 12-Item Short Form Survey Physical Component Score were collected and compared in addition to revision rate, conversion to total hip arthroplasty (THA), and patient satisfaction. RESULTS: Twenty-four of 29 patients (83%) eligible for the study were available for 2-year minimum follow-up with a median follow-up time of 2.5 years (range, 2.0-5.0). There were 19 females and 5 males with mean age of 31 ± 12 years. Mean preoperative lateral center edge angle was 20° ± 5° and alpha angle was 71° ± 11°. One patient underwent reoperation for removal of a symptomatic iliac crest screw at 11.7 months after operation. Two patients, a 33-year-old woman and a 37-year-old man, were converted to THA at 2.6 and 1.3 years, respectively, following the combined procedure. Both patients had a Tönnis grade of 1 on radiographs, as well as bipolar Outerbridge grade III/IV defects requiring microfracture of the acetabulum. For patients who did not convert to THA (n = 22), there was significant improvement from before to after surgery for all scores (P < .05) except SF-12 MCS. The minimal clinically significant difference and patient-acceptable symptom state rates for HOS-ADL, HOS-Sport, and mHHS were 72%, 82%, 86%, and 95%, 91%, and 95%, respectively. Median patient satisfaction was 10 (range, 4 to 10). CONCLUSIONS: Single-stage combined hip arthroscopy with periacetabular osteotomy for patients with symptomatic hip dysplasia results in improvement in PROs and arthroplasty free survivorship of 92% at median 2.5 year follow-up. LEVEL OF EVIDENCE: Level IV, case series.

Biomechanical Analysis of Tibial Motion and ACL Graft Forces After ACLR With and Without LET at Varying Tibial Slopes.

BACKGROUND: Lateral extra-articular tenodesis (LET) is being performed more frequently with anterior cruciate ligament (ACL) reconstruction (ACLR) to decrease graft failure rates. The posterior tibial slope (PTS) affects ACL graft failure rates. The effect of ACLR + LET on tibial motion and graft forces with increasing PTS has not been elucidated. HYPOTHESIS: LET would decrease anterior tibial translation (ATT), tibial rotation, and ACL graft force versus ACLR alone with increasing tibial slope throughout knee range of motion. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve fresh-frozen cadaveric knees (mean donor age, 40.5 years; all female) were tested in 4 conditions (intact, ACL cut, ACLR, and ACLR + LET) with varying PTSs (5°, 10°, 15°, and 20°) at 3 flexion angles (0°, 30°, and 60°). Specimens were mounted to a load frame that applied a 500-N axial load with 1 N·m of internal rotation (IR) torque. The amount of tibial translation, IR, and graft force was measured. RESULTS: Increasing PTS revealed a linear and significant increase in graft force at all flexion angles. LET reduced graft force by 8.3% (-5.8 N) compared with ACLR alone at 30° of flexion. At the same position, slope reduction resulted in reduced graft force by 17% to 22% (-12.3 to -15.2 N) per 5° of slope correction, with a 46% (-40.7 N) reduction seen from 20° to 5° of slope correction. For ATT, ACLR returned tibial translation to preinjury levels, as did ACLR + LET at all flexion angles, except full extension, where ACLR + LET reduced ATT by 2.5 mm compared with the intact state (P = .019). CONCLUSION: Increased PTS was confirmed to increase graft forces linearly. Although ACLR + LET reduced graft force compared with ACLR alone, slope reduction had a larger effect across all testing conditions. No other clinically significant differences were noted between ACLR with versus without LET in regard to graft force, ATT, or IR. CLINICAL RELEVANCE: Many authors have proposed LET in the setting of ACLR, revision surgery, hyperlaxity, high-grade pivot shift, and elevated PTS, but the indications remain unclear. The biomechanical performance of ACLR + LET at varying PTSs may affect daily practice and provide clarity on these indications.

Geriatric Pain Protocol: Impact of Multimodal Pain Care for Elderly Orthopaedic Trauma Patients.

Hip fractures are costly, and associated complications are the leading cause of injury-related deaths in persons 65 years or older. Pain medications in this population can be more potent, have a longer duration of action, and have serious side effects (Chau et al., 2008). Hip fractures are projected to reach 6.26 million worldwide by 2050 (Gullberg et al., 1997; Kannus et al., 1996). Morrison et al. (2003) report that uncontrolled pain leads to increased hospital length of stay (LOS), delayed physical therapy, and long-term functional impairment. The Geriatric Pain Protocol (GPP) is Cedars-Sinai's multimodal pain management solution, addressing the needs of older adult inpatients who have suffered fractures. Can the implementation of GPP reduce the morphine milligram equivalents (MMEs) used, LOS, and postoperative outcomes compared with non-GPP patients? Study participants included hip fracture patients admitted between February 1, 2019, and March 5, 2021; data were collected prospectively from electronic medical records. Inclusion criteria were patients 65 years or older with a hip fracture sustained from a ground-level fall and surgical candidate. Participants were divided into two categories: Geriatric Fracture Program (GFP) and non-GFP, with physician participation in the GFP being the differentiating factor. End points included postoperative pain, postoperative opioid utilization, LOS, complications, and 30-day readmission rates. The Mann-Whitney U test and Fisher's exact test were used for data analysis. Spearman's rank-based correlation coefficient was used to assess associations. The GPP decreased MME daily totals on Days 1 and 2 and improved pain management compared with non-GPP patients. The MMEs were lower in the GPP group than in the non-GPP group for both Postoperative Day 1 (POD1) (p = .007) and POD2 (p = .043); Numerical Rating Scale (NRS) Pain on POD1 was lower in the GPP group (vs. non-GPP, p = .013). There were no group differences in NRS POD2 Pain or complications (all ps > .1). The study sample (N = 453) had no significant difference between sex and LOS (all ps > .3). Although not statistically significant, the 30-day readmission rate trended lower in patients treated in accordance with the GPP. Use of the multimodal GPP reduced pain levels and MME totals for older adult hip fracture inpatients. More data are needed to evaluate the efficiency of the proposed protocol. Future studies should explore the possibilities of using the GPP across the geriatric orthopaedic patient care continuum.

Effects of Lateral Opening-Wedge Distal Femoral Osteotomy on Meniscal Allograft Transplantation: A Biomechanical Evaluation.

Background: Lateral meniscal deficiency with valgus malalignment increases the rate of lateral compartment osteoarthritis. Lateral meniscal allograft transplantation (LMAT) with a concomitant varus-producing opening-wedge distal femoral osteotomy (DFO) is an option yet to be evaluated biomechanically. Purpose/Hypothesis: The purpose of this study was to clarify the biomechanical effects of the realignment procedure in the setting of LMAT. We hypothesized that (1) given the dependence of the lateral compartment on the lateral meniscus, a DFO and increasing degrees of varus would be insufficient to restore lateral compartment pressures to normal from a lateral meniscus-deficient state, and that (2) LMAT would restore lateral compartment pressures to the intact state while DFO would decrease lateral compartment pressures for any given state of the meniscus. Study Design: Controlled laboratory study. Methods: Ten cadaveric knees underwent opening-wedge varus-producing DFO secured by an external fixator. Anatomic alignment was standardized to 6° of mechanical valgus, and each joint was tested in full extension. Submeniscal placement of thin film pressure sensors allowed for the recording of contact pressure, peak contact pressure, and contact area. The specimens were loaded on a biaxial dynamic testing machine with loading angles between 9° valgus and 6° varus of mechanical alignment. Conditions tested included intact meniscus, meniscal deficiency, and meniscal transplantation. Results: Isolated varus-producing DFO to 6° in the meniscus-deficient state failed to restore joint pressures and contact areas to the intact state, with significant changes in mean contact pressure (175%), mean peak contact pressure (135%), and contact area (-41%) (all P < .05 vs intact), while LMAT restored all outcome measures (all P > .05 compared with intact). After LMAT, every additional 1° of DFO correction contributed to a decrease in the mean contact pressure, peak pressure, and contact area of 5.6% (-0.0479 N/mm2), 5.9% (-0.154 N/mm2), and 1.4% (-6.99 mm2) for the lateral compartment and 7.3% (+0.034 N/mm2), 12.6% (+0.160 N/mm2), and 4.3% (+20.53 mm2) for the medial compartment, respectively. Conclusion: Isolated DFO was inadequate to restore load distribution in meniscus-deficient knees, while concomitant LMAT restored near normal forces and improved the lateral compartment biomechanical profile. Clinical Relevance: Our findings support the concomitant use of LMAT and varus-producing DFO in the setting of lateral meniscal deficiency with valgus malalignment. This study provides tools for the orthopaedic surgeon to individualize the correction for each patient.

Outcomes Following Repair of Achilles Midsubstance Tears: Percutaneous Knotless Repair vs Open Repair.

BACKGROUND: Optimum treatment for acute Achilles tendon rupture results in high mechanical strength, low risk of complications, and return to preinjury activity level. Percutaneous knotless repair is a minimally invasive technique with promising results in biomechanical studies, but few comparison clinical studies exist. Our study purpose was to compare functional outcomes and revision rates following acute Achilles tendon rupture treated between percutaneous knotless repair and open repair techniques. METHODS: Patients 18 years or older with an acute Achilles tendon rupture, treated by a single surgeon with either open repair or percutaneous knotless repair, and more than 2 years after surgery were assessed for eligibility. Prospective clinical data were obtained from the data registry and standard electronic medical record. Additionally, the patients were contacted to obtain current follow-up questionnaires. Primary outcome measure was Foot and Ankle Ability Measure (FAAM) activities of daily living (ADL). Secondary outcome measures were FAAM sports, 12-Item Short Form Health Survey (SF-12), Tegner activity scale, patient satisfaction with outcome, complications, and revisions. Postoperative follow-up closest to 5 years was used in this study. RESULTS: In total, 61 patients were included in the study. Twenty-four of 29 patients (83%) in the open repair group and 28 of 32 patients (88%) in the percutaneous knotless repair group completed the questionnaires with average follow-up of 5.8 years and 4.2 years, respectively. We found no significant differences in patient-reported outcomes or patient satisfaction between groups (FAAM ADL: 99 vs 99 points, P = .99). Operative time was slightly longer in the percutaneous knotless repair group (46 vs 52 minutes, P = .02). Two patients in the open group required revision surgery compared to no patients in the percutaneous group. CONCLUSION: In our study, we did not find significant differences in patient-reported outcomes or patient satisfaction by treating Achilles tendon midsubstance ruptures with percutaneous knotless vs open repair. LEVEL OF EVIDENCE: Level IlI, retrospective cohort study.

Broström Repair With and Without Augmentation: Comparison of Outcomes at Median Follow-up of 5 Years.

BACKGROUND: An augmented Broström repair with nonabsorbable suture tape has demonstrated strength and stiffness more similar to the native anterior talofibular ligament (ATFL) compared to Broström repair alone at the time of repair in cadaveric models for the treatment of lateral ankle instability. The study purpose was to compare minimum 2-year patient-reported outcomes (PROs) following treatment of ATFL injuries with Broström repair with vs without suture tape augmentation. METHODS: Between 2009 and 2018, patients >18 years old who underwent primary surgical treatment for an ATFL injury with either a Broström repair alone (BR Cohort) or Broström repair with suture tape augmentation (BR-ST Cohort) were identified. Demographic data and PROs, including Foot and Ankle Ability Measure (FAAM) with activities of daily living (ADL) and sport subscales, 12-Item Short Form Health Survey (SF-12), Tegner Activity Scale, and patient satisfaction with surgical outcome, were compared between groups, and proportional odds ordinal logistic regression was used. RESULTS: Ninety-one of 102 eligible patients were available for follow-up at median 5 years. The BR cohort had 50 of 53 patients (94%) completed follow-up at a median of 7 years. The BR-ST cohort had 41 of 49 (84%) complete follow-up at a median of 5 years. There was no significant difference in median postoperative FAAM ADL (98% vs 98%, P = .67), FAAM sport (88% vs 91%, P = .43), SF-12 PCS (55 vs 54, P = .93), Tegner score (5 vs 5, P = .64), or patient satisfaction (9 vs 9, P = .82). There was significantly higher SF-12 MCS (55.7 vs 57.6, P = .02) in the BR-ST group. Eight patients underwent subsequent ipsilateral ankle surgery, of which one patient (BR-ST group) was revised for recurrent lateral ankle instability. CONCLUSION: At median 5 years, patients treated for ATFL injury of the lateral ankle with Broström repair with suture tape augmentation demonstrated similar patient-reported outcomes to those treated with Broström repair alone. LEVEL OF EVIDENCE: Level II, retrospective cohort study.

Losartan in Combination With Bone Marrow Stimulation Showed Synergistic Effects on Load to Failure and Tendon Matrix Organization in a Rabbit Model.

PURPOSE: To investigate the effects of combining bone marrow stimulation (BMS) with oral losartan to block transforming growth factor ß1 (TGF-ß1) on biomechanical repair strength in a rabbit chronic injury model. METHODS: Forty rabbits were randomly allocated into 4 groups (10 in each group). The supraspinatus tendon was detached and left alone for 6 weeks to establish a rabbit chronic injury model and was then repaired in a surgical procedure using a transosseous, linked, crossing repair construct. The animals were divided into the following groups: control group (group C), surgical repair only; BMS group (group B), surgical repair with BMS of the tuberosity; losartan group (group L), surgical repair plus oral losartan (TGF-ß1 blocker) for 8 weeks; and BMS-plus-losartan group (group BL), surgical repair plus BMS plus oral losartan for 8 weeks. At 8 weeks after repair, biomechanical and histologic evaluations were performed. RESULTS: The biomechanical testing results showed significantly higher ultimate load to failure in group BL than in group B (P = .029) but not compared with group C or group L. A 2 × 2 analysis-of-variance model found that the effect of losartan on ultimate load significantly depended on whether BMS was performed (interaction term F1,28 = 5.78, P = .018). No difference was found between the other groups. No difference in stiffness was found between any groups. On histologic assessment, groups B, L, and BL showed improved tendon morphology and an organized type I collagen matrix with less type III collagen compared with group C. Group BL showed the most highly organized tendon matrix with more type I collagen and less type III collagen, which indicates less fibrosis. Similar results were found at the bone-tendon interface. CONCLUSIONS: Rotator cuff repair combined with oral losartan and BMS of the greater tuberosity showed improved pullout strength and a highly organized tendon matrix in this rabbit chronic injury model. CLINICAL RELEVANCE: Tendon healing or scarring is accompanied by the formation of fibrosis, which has been shown to result in compromised biomechanical properties, and is therefore a potential limiting factor in healing after rotator cuff repair. TGF-ß1 expression has been shown to play an important role in the formation of fibrosis. Recent studies focusing on muscle healing and cartilage repair have found that the downregulation of TGF-ß1 by losartan intake can reduce fibrosis and improve tissue regeneration in animal models.

Minimum 5-Year Clinical Outcomes of Arthroscopically Repaired Massive Rotator Cuff Tears: Effect of Age on Clinical Outcomes.

BACKGROUND: Massive rotator cuff tears (MRCTs) can be challenging to treat, and the efficacy of repair of MRCTs in older patients has been debated. PURPOSE: To report minimum 5-year outcomes after primary arthroscopic rotator cuff repair of MRCT and determine whether age affects outcomes. STUDY DESIGN: Case series; Level of evidence 4. METHODS: The study included consecutive patients with MRCTs who were treated with arthroscopic rotator cuff repair by a single surgeon between February 2006 and October 2016. MRCTs were defined as ≥2 affected tendons with tendon retraction to the glenoid rim and/or a minimum exposed greater tuberosity of ≥67. Patient-reported outcome (PRO) data collected preoperatively and at a minimum of 5 years included the American Shoulder and Elbow Surgeons (ASES) score; Single Assessment Numeric Evaluation (SANE) score; the shortened version of the Disabilities of the Arm, Shoulder and Hand score (QuickDASH); the 12-Item Short Form Health Survey (SF-12) Physical Component Summary (PCS); and patient satisfaction. Surgical failure was defined as subsequent revision rotator cuff surgery or conversion to reverse total shoulder arthroplasty. Regression analysis was performed to determine whether age had an effect on clinical outcomes. RESULTS: A total of 53 shoulders in 51 patients (mean age, 59.7 years; range, 39.6-73.8 years; 34 male, 19 female) met inclusion criteria with a mean follow-up of 8.1 years (range, 5.0-12.1 years). Three shoulders (5.7%) failed at 2.4, 6.0, and 7.1 years. Minimum 5-year follow-up was obtained in 45 of the remaining 50 shoulders (90%). Mean PROs improved as follows: ASES from 58.8 to 96.9 (P < .001), SANE from 60.5 to 88.5 (P < .001), QuickDASH from 34.2 to 6.8 (P < .001), and SF-12 PCS from 41.1 to 52.2 (P < .001). Patient satisfaction was a median of 10 (on a scale of 1-10). Age was not associated with any PRO measures postoperatively (P > .05). CONCLUSION: This study demonstrated significantly improved clinical scores, decreased pain, and increased return to activity for patients with MRCT at midterm follow-up (mean, 8.1 years; range, 5.0-12.1 years). In this patient cohort, no association was found between age and clinical outcomes.

Biomechanical Evaluation of Posterior Shoulder Instability With a Clinically Relevant Posterior Glenoid Bone Loss Model.

BACKGROUND: Existing biomechanical studies of posterior glenoid bone loss and labral pathology are limited by their use of anterior instability models, which differ in both orientation and morphology and have been performed in only a single, neutral arm position. PURPOSE: To evaluate the biomechanical effectiveness of a posterior labral repair in the setting of a clinically relevant posterior bone loss model in various at-risk arm positions. STUDY DESIGN: Controlled laboratory study. METHODS: Ten fresh-frozen cadaveric shoulders were tested in 7 consecutive states using a 6 degrees of freedom robotic arm: (1) native, (2) posterior labral tear (6-9 o'clock), (3) posterior labral repair, (4) mean posterior glenoid bone loss (7%) with labral tear, (5) mean posterior glenoid bone loss with labral repair, (6) large posterior glenoid bone loss (28%) with labral tear, and (7) large posterior glenoid bone loss with labral repair. Bone loss was created using 3-dimensional printed computed tomography model templates. Biomechanical testing consisted of 75 N of posterior-inferior force and 75 N of compression at 60° and 90° of flexion and scaption. Posterior-inferior translation, lateral translation, and peak dislocation force were measured for each condition. RESULTS: Labral repair significantly increased dislocation force independent of bone loss state between 10.1 and 14.8 N depending on arm position. Dislocation force significantly decreased between no bone loss and small bone loss (11.9-13.5 N), small bone loss and large bone loss (9.4-14.3 N), and no bone loss and large bone loss (21.2-26.5 N). Labral repair significantly decreased posterior-inferior translation compared with labral tear states by a range of 1.0 to 2.3 mm. In the native state, the shoulder was most unstable in 60° of scaption, with 29.9 ± 6.1-mm posterior-inferior translation. CONCLUSION: Posterior labral repair improved stability of the glenohumeral joint, and even in smaller to medium amounts of posterior glenoid bone loss the glenohumeral stability was maintained with labral repair in this cadaveric model. However, a labral repair with large bone loss could not improve stability to the native state. CLINICAL RELEVANCE: This study shows that larger amounts of posterior glenoid bone loss (>25%) may require bony augmentation for adequate stability.

Use of Computed Tomography in the Evaluation of Anterior Shoulder Instability: Possible Effect on Surgical Management.

BACKGROUND: Glenoid bone loss is a critical factor in the management of anterior shoulder instability (ASI). Computed tomography (CT) is often considered the gold standard to evaluate glenoid bone loss, but it is associated with negative factors such as radiation. Thus, interest exists as to when orthopaedic surgeons need a CT scan to guide decision-making when treating ASI. PURPOSE: To determine whether information gained from a shoulder CT scan alters orthopaedic surgeons' management plan for ASI and, secondarily, to determine whether surgeon- and patient-specific factors affect whether a CT scan changes treatment and which clinical factors are most important in surgical decision-making. STUDY DESIGN: Cross-sectional study. METHODS: A questionnaire composed of 24 ASI vignettes was administered to Herodicus Society members, American Shoulder and Elbow Surgeons Neer Circle members, and sports medicine fellowship-trained orthopaedic surgeons. Participants chose their recommended surgical treatment from the options of arthroscopic Bankart repair, open Bankart repair, bony reconstruction procedure, or other based on patient history, radiographs, and magnetic resonance imaging. Participants were then shown CT images and asked whether their treatment plan changed and, if not, whether the CT scan was not necessary or had reinforced their decision. Generalized linear mixed-effects logistic regression modeling was performed to assess the influence of vignette and respondent characteristics on treatment decisions. RESULTS: A total of 74 orthopaedic surgeons completed the survey; 96% were fellowship trained (sports medicine, 50%; shoulder and elbow surgery, 41%), and 66% practiced in academic settings. CT imaging did not change the selected treatment strategy in 75.6% of responses. In cases when management did not change, surgeons reported that the CT scan reinforced their decision in 53.4% of responses and was not necessary for decision-making in 22.2% of responses. Decision-making was more likely to be changed after CT in male patients and those with off-track lesions. CONCLUSION: Information gained from a CT scan did not alter treatment decision-making in three-quarters of vignettes among surgeons experienced in the management of ASI. The finding that CT scans did alter the treatment plan in nearly a quarter of cases is not insignificant, and it appears that in patients with borderline glenoid track status and few other risk factors for recurrence after arthroscopic stabilization, CT imaging is more likely to change management.

Effect of Posterior Malleolar Fixation on Syndesmotic Stability.

BACKGROUND: Transsyndesmotic fixation with suture buttons (SBs), posterior malleolar fixation with screws, and anterior inferior tibiofibular ligament (AITFL) augmentation using suture tape (ST) have all been suggested as potential treatments in the setting of a posterior malleolar fracture (PMF). However, there is no consensus on the optimal treatment for PMFs. PURPOSE: To determine which combination of (1) transsyndesmotic SBs, (2) posterior malleolar screws, and (3) AITFL augmentation using ST best restored native tibiofibular and ankle joint kinematics after 25% and 50% PMF. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty cadaveric lower-leg specimens were divided into 2 groups (25% or 50% PMF) and underwent biomechanical testing using a 6 degrees of freedom robotic arm in 7 states: intact, syndesmosis injury with PMF, transsyndesmotic SBs, transsyndesmotic SBs + AITFL augmentation, transsyndesmotic SBs + AITFL augmentation + posterior malleolar screws, posterior malleolar screws + AITFL augmentation, and posterior malleolar screws. Four biomechanical tests were performed at neutral and 30° of plantarflexion: external rotation, internal rotation, posterior drawer, and lateral drawer. The position of the tibia, fibula, and talus were recorded using a 5-camera motion capture system. RESULTS: With external rotation, posterior malleolar screws with AITFL augmentation resulted in best stability of the fibula and ankle joint. With internal rotation, all repairs that included posterior malleolar screws stabilized the fibula and ankle joint. Posterior and lateral drawer resulted in only small differences between the intact and injured states. No differences were found in the efficacy of treatments between 25% and 50% PMFs. CONCLUSION: Posterior malleolar screws resulted in higher syndesmotic stability when compared with transsyndesmotic SBs. AITFL augmentation provided additional external rotational stability when combined with posterior malleolar screws. Transsyndesmotic SBs did not provide any additional stability and tended to translate the fibula medially. CLINICAL RELEVANCE: Posterior malleolar fixation with AITFL augmentation using ST may be the preferred surgical method when treating patients with acute ankle injury involving an unstable syndesmosis and a PMF ≥25%.

In situ repair of segmental loss posterior lateral meniscal root tears outperforms meniscofemoral ligament imbrication in the ACL reconstructed knee.

PURPOSE: The purpose of this study was to compare the biomechanical effect of in-situ repair of posterior lateral meniscal root (PLMR) tear with segmental meniscal loss, with and without meniscofemoral ligament (MFL) imbrication, on anterior cruciate ligament (ACL) graft force and knee joint kinematics. METHODS: Ten fresh-frozen cadaveric knee specimens underwent kinematic evaluation in five states: 1) Native, 2) ACLR, 3) Segmental PLMR loss, 4) In-situ PLMR repair, and 5) MFL augmentation. Kinematic evaluation consisted of five tests, each performed at full extension and at 30° of flexion: 1) Anterior drawer, 2) Internal Rotation, 3) External Rotation, 4) Varus, and 5) Valgus. Additionally, a simulated pivot shift test was performed. Knee kinematics and ACL graft force were measured. RESULTS: PLMR tear did not significantly increase ACL graft force in any test. However, PLMR repair significantly reduced ACL graft force compared to the ACLR alone (over constraint -26.6 N, p = 0.001). PLMR tear significantly increased ATT during the pivot shift test (+ 2.7 mm, p = 0.0001), and PLMR repair restored native laxity. MFL augmentation did not improve the mechanics. CONCLUSIONS: In-situ PLMR repair eliminated pivot shift laxity through ATT and reduced force on the ACL graft, indicating that this procedure may be ACL graft-protective. MFL augmentation was not shown to have any effect on graft force or knee kinematics and untreated PLMR tears may place an ACL graft at higher risk. This study suggests concomitant repair to minimize additional forces on the ACL graft.

Preventing varus collapse in proximal humerus fracture fixation: 90-90 dual plating versus endosteal fibular allograft strut.

INTRODUCTION: Screw cut out and varus collapse are the most common complication of locked plate fixation of proximal humerus fractures. The purpose of this study was to compare dual plating and endosteal fibular allograft struts as augmentation strategies to prevent varus collapse. MATERIALS AND METHODS: A trapezoidal osteotomy was created at the metaphysis to create a 2-part proximal humerus model in 18 paired shoulder specimens. Each specimen was assigned to group A, B, or C and was fixed with either a lateral locking plate, a lateral locking plate and anterior one-third tubular plate in an orthogonal 90/90 configuration, or a lateral locking plate with intramedullary fibular strut, respectively. The specimens were stressed in axial compression to failure. Displacement, elastic limit, ultimate load, and stiffness were recorded and calculated. RESULTS: There was no difference in mean cyclic displacement between the three groups (0.71 mm vs 0.89 mm vs 0.61 mm for Group A, B, C, respectively). Lateral plating demonstrated the greatest absolute and relative displacement at the elastic limit (5.3 mm ± 1.5 and 4.4 mm ± 1.3) without significance. The elastic limit or yield point was greatest for fibular allograft, Group C (1223 N ± 501 vs 1048 N ± 367 for Group B and 951 N ± 249 for Group A) without significance. CONCLUSIONS: Dual plating of proximal humerus fractures in a 90-90 configuration demonstrates similar biomechanical properties as endosteal fibular strut allograft. Both strategies demonstrate superior stiffness to isolated lateral locked plating.

Superior Capsule Reconstruction Using Acellular Dermal Allograft Secured at 45° of Glenohumeral Abduction Improves the Superior Stability of the Glenohumeral Joint in Irreparable Massive Posterosuperior Rotator Cuff Tears.

PURPOSE: The purpose of the current study was to create a dynamic cadaveric shoulder model to determine the effect of graft fixation angle on shoulder biomechanics following SCR and to assess which commonly used fixation angle (30° vs 45° of abduction) results in superior glenohumeral biomechanics. METHODS: Twelve fresh-frozen cadaveric shoulders were evaluated using a dynamic shoulder testing system. Humeral head translation, subacromial and glenohumeral contact pressures were compared among 4 conditions: 1) Intact, 2) Irreparable supra- and infraspinatus tendon tear, 3) SCR using acellular dermal allograft (ADA) fixation at 30° of abduction, and 4) SCR with ADA fixation at 45° of abduction. RESULTS: SCR at both 30° (0.287 mm, CI: -0.480 - 1.05 mm; P < .0001) and 45° (0.528 mm, CI: -0.239-1.305 mm; P = .0006) significantly decreased superior translation compared to the irreparably torn state. No significant changes in subacromial peak contact pressure were observed between any states. The average glenohumeral contact pressure increased significantly following creation of an irreparable RCT (373 kPa, CI: 304-443 vs 283 kPa, CI 214-352; P = .0147). The SCR performed at 45° (295 kPa, CI: 226-365, P = .0394) of abduction significantly decreased the average glenohumeral contact pressure compared to the RCT state. There was no statistically significant difference between the average glenohumeral contact pressure of the intact state and SCR at 30° and 45°. CONCLUSION: SCR improved the superior stability of the glenohumeral joint when the graft was secured at 30° or 45° of glenohumeral abduction. Fixation at 45° of glenohumeral abduction provided more stability than did fixation at 30°. CLINICAL RELEVANCE: Grafts attached at 45° of glenohumeral abduction biomechanically restore the glenohumeral stability after SCR using ADA better than fixation at 30° of glenohumeral abduction.

The revision hip arthroscopy complex: capsular deficiency, labral deficiency, femoral over-resection and adhesions can result in good survivorship with revision hip arthroscopy.

To evaluate the patient-reported outcomes (PROs) and survivorship of combined arthroscopic hip labral reconstruction/augmentation, capsular reconstruction, femoral neck remplissage and lysis of adhesions. Patients ≥18 years old who underwent this combination of procedures during revision hip arthroscopy and were eligible for minimum 2-year follow-up were identified. PRO scores including Hip Outcome Score (HOS)-Activities of Daily Living scale, HOS-Sports scale, modified Harris Hip Score, Short Form 12, and Western Ontario & McMaster Universities Osteoarthritis Index, patient satisfaction and failure rates were analyzed. Seven patients (5 females and 2 males) with average age of 45.0 ± 5.2 (range: 40-54 years) met inclusion criteria. Patients had a median of 1 (range: 1-3) prior hip surgery at an outside institution. All patients had previously undergone femoral osteoplasty, and 85% (6/7) of patients had a labral repair performed. Four patients had no capsule closure performed in their prior procedures. Six patients were available for minimum 2-year follow-up. Two patients converted to total hip arthroplasty: one patient with four prior hip arthroscopies and the other had advanced osteoarthritis with outerbridge grade 3/4 defects requiring microfracture. Mean patient satisfaction was 7 (range: 2-9). At mean follow-up of 3 years, most patients who underwent the combination of labral reconstruction, capsular reconstruction, femoral neck remplissage and lysis of adhesions during revision hip arthroscopy demonstrated improved PROs. This salvage procedure has the potential to restore hip function in patients who have failed an initial hip arthroscopy procedure. In patients with these pathologies present and concomitant joint space narrowing, a total hip arthroplasty may be a more appropriate salvage option.

Glenoid retroversion does not impact clinical outcomes or implant survivorship after total shoulder arthroplasty with minimal, noncorrective reaming.

Hypothesis: Both clinical outcomes and early rates of failure will not be associated with glenoid retroversion. Methods: All patients who underwent an anatomic total shoulder arthroplasty with minimal, noncorrective reaming between 2006 and 2016 with minimum 2-year follow-up were reviewed. Measurements for retroversion, inclination, and posterior subluxation were obtained from magnetic resonance imaging or computerized tomography. A regression analysis was performed to assess the association between retroversion, inclination and subluxation, and their effect on patient reported outcomes (PROs). Clinical failures and complications were reported. Results: One hundred fifty-one anatomic total shoulder arthroplasties (90% follow-up) with a mean follow-up of 4.6 years (range, 2-12 years) were assessed. The mean preoperative retroversion was 15.6° (range, 0.2-42.1), the mean posterior subluxation was 15.1% (range, -3.6 to 44.1%), and the mean glenoid inclination was 13.9° (range, -11.3 to 44.3). All median outcome scores improved significantly from pre- to post-operatively (P < .001). The median satisfaction was 10/10 (1st quartile = 7 and 3rd quartile = 10). Linear regression analysis found no significant association between retroversion and any postoperative PRO. A total of 5 (3.3%) failures occurred due to glenoid implant loosening (3 patients) and Cutibacterium acnes infection (2 patients) with no association between failure causation and increased retroversion or inclination. No correlation could be found between the Walch classification and postoperative PROs. Conclusion: Anatomic total shoulder replacement with minimal and noncorrective glenoid reaming demonstrates reliable increases in patient satisfaction and clinical outcomes at a mean of 4.6-year follow-up in patients with up to 40° of native retroversion. Higher values of retroversion were not associated with early deterioration of clinical outcomes, revisions, or failures. Long-term studies are needed to see if survivorship and outcomes hold up over time.

The recovery curve of anatomic total shoulder arthroplasty for primary glenohumeral osteoarthritis: midterm results at a minimum of 5 years.

Background: Excellent results have been reported for anatomic total shoulder arthroplasty (TSA) for the treatment of primary glenohumeral osteoarthritis (GHOA). We aim to assess the recovery curve and longitudinal effects of time, age, sex, and glenoid morphology on patient-reported outcomes (PROs) after primary anatomic TSA for primary GHOA. Methods: Patients who underwent primary anatomic TSA over 5 years ago were included: Short-Form 12 Physical Component Summary, American Shoulder and Elbow Surgeons scores, Quick Disabilities of the Arm Shoulder and Hand Score, Single Assessment Numeric Evaluation, and patient satisfaction were assessed. Linear mixed-effects models were used to model progression in PROs longitudinally. Unadjusted models and models controlling for sex and age were constructed. Results: Eighty-one patients (91 shoulders) were included. Significant improvements from the preoperative period to 1 year postoperatively in the median American Shoulder and Elbow Surgeons (48 to 93; P < .001), Quick Disabilities of the Arm Shoulder and Hand Score (42 to 11; P < .001), Single Assessment Numeric Evaluation (50 to 91; P < .001), and Short-Form 12 Physical Component Summary (35 to 53; P = .004) scores were noted. No significant decrease was observed for any of the outcome scores. Median satisfaction at the final follow-up was 10 out of 10. At 1, 2, 3, 4, 5, 6, and 7 years postoperatively, 77%, 64%, 79%, 57%, 86%, 56%, and 78% of patients, respectively, reported sports participation equal to or slightly below preinjury level. There was no association between the glenoid morphology and functional outcomes. Conclusion: Patients undergoing anatomic TSA for primary GHOA showed excellent improvement in PROs and satisfaction in the first year, and these results were maintained postoperatively for a minimum of 5 years. Age- and sex-adjusted models or glenoid morphology did not substantially alter any trends in PROs postoperatively.