Anterior Cruciate Ligament Reconstruction: Fixation Techniques.

Anterior cruciate ligament reconstruction (ACLR) is among the most common procedures performed by orthopaedic sports medicine surgeons and has inherent challenges due to the complex anatomy and biomechanical properties required to reproduce the function and stability of the native ACL. Awareness of the anatomic and biomechanical factors, including graft selection and tunnel placement, along with graft tensioning and fixation techniques, is vital in achieving a successful clinical outcome. Common techniques for ACLR graft fixation include intratunnel fixation with interference screws, suspensory fixation, or hybrid fixation strategies, along with several supplemental fixation techniques. Interference screw fixation may decrease graft-tunnel motion, tunnel widening, and graft creep and may be performed with metallic, PEEK (polyether ether ketone), or bioabsorbable screws. Suspensory fixation techniques primarily include suture-buttons, anchors, staples, and screws/washers. Suspensory fixation allows adequate biomechanical strength, although some techniques have been linked to increased graft-tunnel motion and potential tunnel widening. Supplemental fixation techniques may be performed in the setting of concerns for adequacy of primary fixation and includes the use of suture anchors, staples, and screw/washer devices. Regardless of the implant chosen for fixation, secure fixation is paramount to avoid displacement of the graft and allow for integration into the bone tunnel and facilitates early postoperative rehabilitation. It is important for orthopaedic sports medicine surgeons performing primary and revision ACLR to be familiar with multiple fixation techniques.

Editorial Commentary: Evaluation for Cartilage Lesions on Magnetic Resonance Imaging Continues to Improve: Artificial Intelligence Applications May Result in Higher Sensitivity and Specificity.

Accurate detection of cartilage lesions of the knee is required to offer patient-specific care and can alter surgical intervention options. To date, diagnostic arthroscopy remains the gold standard yet often requires the need for staged operative procedure for treatment. Magnetic resonance imaging (MRI) is the most accurate imaging modality with high specificity, yet even with recent advances, MRI has limited specificity. Newer scanners (3 T) and updated scanning sequences (3-dimensional MRI and quantitative MRI) are most sensitive in characterizing cartilage lesions of the knee, but these resources are not available to all users. Promising new avenues for patient-specific MRI scans along with the utilization of artificial intelligence will more accurately identify and quantify lesion size, location, and depth.

Posterior Shoulder Instability, Part I-Diagnosis, Nonoperative Management, and Labral Repair for Posterior Shoulder Instability-An International Expert Delphi Consensus Statement.

PURPOSE: To establish consensus statements on the diagnosis, nonoperative management, and labral repair for posterior shoulder instability. METHODS: A consensus process on the treatment of posterior shoulder instability was conducted, with 71 shoulder/sports surgeons from 12 countries participating on the basis of their level of expertise in the field. Experts were assigned to 1 of 6 working groups defined by specific subtopics within posterior shoulder instability. Consensus was defined as achieving 80% to 89% agreement, whereas strong consensus was defined as 90% to 99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement. RESULTS: Unanimous agreement was reached on the indications for nonoperative management and labral repair, which include whether patients had primary or recurrent instability, with symptoms/functional limitations, and whether there was other underlying pathology, or patient's preference to avoid or delay surgery. In addition, there was unanimous agreement that recurrence rates can be diminished by attention to detail, appropriate indication and assessment of risk factors, recognition of abnormalities in glenohumeral morphology, careful capsulolabral debridement and reattachment, small anchors with inferior placement and multiple fixation points that create a bumper with the labrum, treatment of concomitant pathologies, and a well-defined rehabilitation protocol with strict postoperative immobilization. CONCLUSIONS: The study group achieved strong or unanimous consensus on 63% of statements related to the diagnosis, nonoperative treatment, and labrum repair for posterior shoulder instability. The statements that achieved unanimous consensus were the relative indications for nonoperative management, and the relative indications for labral repair, as well as the steps to minimize complications for labral repair. There was no consensus on whether an arthrogram is needed when performing advanced imaging, the role of corticosteroids/orthobiologics in nonoperative management, whether a posteroinferior portal is required. LEVEL OF EVIDENCE: Level V, expert opinion.

Posterior Shoulder Instability Part II - Glenoid Bone-Grafting, Glenoid Osteotomy, and Rehabilitation/Return to Play - An International Expert Delphi Consensus Statement.

PURPOSE: The purpose of this study was to establish consensus statements on glenoid bone-grafting, glenoid osteotomy, rehabilitation, return to play, and follow-up for posterior shoulder instability. METHODS: A consensus process on the treatment of posterior shoulder instability was conducted, with 71 shoulder/sports surgeons from 12 countries participating based on their level of expertise in the field. Experts were assigned to one of 6 working groups defined by specific subtopics within posterior shoulder instability. Consensus was defined as achieving 80-89% agreement, whereas strong consensus was defined as 90-99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement. RESULTS: All of the statements relating to rehabilitation, return to play, and follow-up achieved consensus. There was unanimous consensus that the following criteria should be considered: restoration of strength, range of motion, proprioception, and sport-specific skills, with a lack of symptoms. There is no minimum time point required to return to play. Collision athletes and military athletes may take longer to return because of their higher risk for recurrent instability, and more caution should be exercised in clearing them to return to play, with elite athletes potentially having different considerations in returning to play. The relative indications for revision surgery are symptomatic apprehension, multiple recurrent instability episodes, further intra-articular pathologies, hardware failure, and pain. CONCLUSION: The study group achieved strong or unanimous consensus on 59% of statements. Unanimous consensus was reached regarding the criteria for return to play, collision/elite athletes having different considerations in return to play, indications for revision surgery, and imaging only required as routine for those with glenoid bone-grafting/osteotomies at subsequent follow-ups. There was no consensus on optimal fixation method for a glenoid bone-block, the relative indications for glenoid osteotomy, whether fluoroscopy is required or if the labrum should be concomitantly repaired. LEVEL OF EVIDENCE: Level V Expert Opinion.

Impact of the COVID-19 Pandemic on Sports Medicine Patient Care.

The COVID-19 pandemic has necessitated new practices in sports medicine patient care. Telehealth has been validated as a reliable tool for consultations and physical examinations and increases access to care in a cost-efficient manner. Social distancing and avoiding team members who have tested positive are the most effective ways to reduce spread. For screening, daily self-reported symptom checklists and fever monitoring help identify potentially infected athletes who should be instructed to isolate and seek care. Polymerase chain-reaction (PCR) testing for the virus via nasopharyngeal swab is not recommended for screening and should be reserved for symptomatic individuals with fever, cough, or shortness of breath. Face masks and personal protective equipment (PPE) may be beneficial in high-risk settings, but there is little evidence to support use in athletic populations. Median return to play after COVID-19 in elite athletes has been reported as 18 days (range: 12 to 30), with 27% not fully available at 28 days. Chest pain at diagnosis was the only symptom associated with time loss longer than 28 days. Finally, canceled competitions or time loss results in grief, stress, and frustration for athletes, as well as loss of a social support network and routine training regimens. Mental health support services may be indicated.

Perioperative Gabapentin May Reduce Opioid Requirement for Early Postoperative Pain in Patients Undergoing Anterior Cruciate Ligament Reconstruction: A Systematic Review of Randomized Controlled Trials.

PURPOSE: To evaluate the efficacy of perioperative gabapentin or pregabalin treatment on postoperative pain and opioid requirement reduction in patients undergoing anterior cruciate ligament reconstruction (ACLR). METHODS: A systematic review of randomized control trials was conducted evaluating the effect of gabapentin or pregabalin on postoperative pain and opioid requirement for patients undergoing ACLR. The primary outcomes assessed were postoperative pain scores and opioid requirements. Secondary outcomes were complications, side effects, dosage, and timing of intervention. RESULTS: The initial search query identified 151 studies and 6 studies were included after full-text articles were reviewed. Three studies investigated the use of gabapentin and three studies investigated pregabalin. All three gabapentin studies reported significantly decreased or equivalent pain scores while also significantly reducing or removing total opioid consumption compared to control groups. Pregabalin demonstrated inconsistent efficacy for pain control and opioid consumption parameters across three studies. One study (pregabalin, n = 1) reported significantly increased incidence of dizziness with pregabalin compared to placebo. CONCLUSIONS: There is moderate evidence demonstrating that preoperative gabapentin may be safe and effective in reducing postoperative pain and opioid consumption after ACLR. Gabapentin may be considered when employed as part of a multimodal analgesia regimen; however, the optimal protocol has yet to be determined. Currently, there is limited evidence demonstrating the efficacy of pregabalin on pain and opioid consumption in the setting of ACLR. LEVEL OF EVIDENCE: Level I, systematic review of Level I Studies.

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.

Improved Accuracy of Coronal Alignment Can Be Attained Using 3D-Printed Patient-Specific Instrumentation for Knee Osteotomies: A Systematic Review of Level III and IV Studies.

PURPOSE: To evaluate the accuracy and precision of postoperative coronal plane alignment using 3D-printed patient-specific instrumentation (PSI) in the setting of proximal tibial or distal femoral osteotomies. METHODS: A systematic review evaluating the accuracy of 3D-printed PSI for coronal plane alignment correcting knee osteotomies was performed. The primary outcomes were accuracy of coronal plane limb alignment correction and number of correction outliers. Secondary variables were duration of surgery, number of intraoperative fluoroscopic images, complications, cost, and clinical outcomes (as applicable). RESULTS: Ninety-three studies were identified, and 14 were included in the final analysis. Overall, mean postoperative deviation from target correction ranged from 0.3° to 1° for all studies using hip-knee angle measurements and 2.3% to 4.9% for all studies using weight-bearing line measurements. The incidence of correction outliers was assessed in 8 total studies and ranged from 0 to 25% (total n = 10 knees) of patients corrected with 3D-printed PSI. Osteotomies performed with 3D-printed cutting guides or wedges demonstrated significantly shorter operative times (P < .05) and fewer intraoperative fluoroscopic images (P < .05) than control groups in four case control studies. CONCLUSION: Patients undergoing distal femoral osteotomy or proximal tibial osteotomy procedures with 3D-printed patient-specific cutting guides and wedges had highly accurate coronal plane alignment with a low rate of outliers. Patients treated with 3D printed PSI also demonstrated significantly shorter operative times and decreased intraoperative fluoroscopy when compared to conventional techniques. LEVEL OF EVIDENCE: Level IV, systematic review of Level III-IV studies.

Acute Intervention With Selective Interleukin-1 Inhibitor Therapy May Reduce the Progression of Posttraumatic Osteoarthritis of the Knee: A Systematic Review of Current Evidence.

PURPOSE: To evaluate the efficacy of selective interleukin (IL)-1 inhibitor therapy in the reduction of posttraumatic osteoarthritis (PTOA) progression following knee ligament or meniscal injury. METHODS: A systematic review was conducted evaluating the disease-modifying efficacy of selective IL-1 inhibition in the setting of knee PTOA. RESULTS: The literature search identified 364 articles and 11 studies were included (n = 10 preclinical, n = 1 clinical). Drug delivery in preclinical studies was administered using IL-1Ra-encoded helper-dependent adenovirus particles (n = 3), synovial cells transfected with an IL-1Ra-encoded retroviral vector (n = 3), or varying chemical compositions of nonviral microcapsule gene carriers (n = 4). Intervention with selective IL-1 inhibitor therapy within 2 weeks of injury provided the greatest protective benefits in reducing the progression of PTOA regardless of drug delivery methodology in preclinical models. The majority of studies reported significantly better cartilage integrity and reduction in lesion size in animals treated with gene therapy with the greatest effects seen in those treated within 5 to 7 days of injury. CONCLUSIONS: Early intervention with selective IL-1 inhibitor therapy were effective in reducing proinflammatory IL-1ß levels in the acute and subacute phases following traumatic knee injury in preclinical animal model studies, while significantly reducing cartilage damage, lesion size, and PTOA progression at short-term follow-up. However, it was found that the effect of these therapies diminished over time. CLINICAL RELEVANCE: Acute, intra-articular injection of selective IL-1 inhibitors may reduce PTOA progression, supporting the need for additional basic and clinical investigation.

Meniscal Repair Techniques for Middle- and Posterior-Third Tears.

Technical advancements in meniscal repairs have greatly contributed to the ability to repair a variety of meniscal tears that were once thought untreatable. The gold-standard treatment for arthroscopic meniscal body repair remains an inside-out technique. The advantages of this technique are innate to the low-profile nature of the suture-passing construct, which allows for perpendicular access to tears with the benefit of multiple fixation points, in contrast to often bulkier all-inside repair devices. This technique requires a posteromedial or posterolateral incision for safe suture passing and needle retrieval and necessitates a surgical team experienced in this method of repair. However, the newest generation of all-inside devices has allowed for more facile placement of a variety of suture types. The all-inside repair technique includes both capsular-based and meniscal-based fixation, is not limited by a need for additional experienced surgical personnel to pass and retrieve needles, and does not require additional incisions. Regardless of fixation type, meniscal repair has been shown to improve long-term functional scores when compared with meniscectomy. Additionally, biological adjuncts have been introduced into the repair algorithm to improve healing rates when performing isolated meniscal repairs. Preparing the healing site with abrasion or trephination creates vascular channels that can facilitate repair. Intercondylar-notch marrow venting attempts to replicate the environment created by anterior cruciate ligament drilling for which healing rates are notably higher than those with isolated meniscal repairs. The use of fibrin clots in inside-out meniscal repairs with suturing of the clot to the area of the tear has also shown promising early healing rates on both magnetic resonance imaging and second-look arthroscopy. Finally, biological adjuncts such as platelet-rich plasma and concentrated bone marrow aspirate have shown both early clinical and radiographic improvements in Level IV case series, but further research is needed to more definitively measure their utility in the setting of meniscal repair.

Editorial Commentary: Rotator Cable Compromise May Not Always Result in Poor Shoulder Function.

Compromise of the rotator cable has been linked with poor shoulder function in patients with rotator cuff tears. Yet, some patients remain asymptomatic with relatively good function despite rotator cuff tear pathology. Dynamic changes in co-contraction of opposing muscle groups throughout full range of motion have a significant effect on the stability of the shoulder joint. Advancements in biomechanical shoulder models have allowed investigators to diverge from historically static methods to more physiologic dynamic tests, which may provide stronger and more meaningful evidence when applied clinically. Nevertheless, with limitations seen in cadaveric models, the findings observed in live patients under fluoroscopic evaluation with known rotator cuff tear patterns remain a gold standard and practical way to approach the pathologic biomechanical environment of the rotator cuff tear compromised shoulder. The functional status of the glenohumeral joint and the integrity of various aspects of the rotator cuff remain a key part of clinical decision-making in approaches of rotator cuff repair (decompression and debridement, partial repair, margin convergence, augmentations, releases, double-row repairs), tendon transfers, superior capsular reconstructions, resurfacing options, and even considerations of arthroplasty.

Preventative and Disease-Modifying Investigations for Osteoarthritis Management Are Significantly Under-represented in the Clinical Trial Pipeline: A 2020 Review.

PURPOSE: To conduct a review of active United States-based clinical trials investigating preventative, symptom resolution, and disease-modifying therapies for osteoarthritis (OA). METHODS: We conducted a review of currently active clinical trials for OA using data obtained from the ClinicalTrials.gov database as of August 2020. The inclusion criteria were active studies registered in the United States that involved the prevention, symptom resolution, or disease modification of OA. Descriptive statistics were recorded and summarized. RESULTS: A total of 3,859 clinical trials were identified, and 310 were included in the final analysis. Of the currently active trials, 89% (n = 275) targeted symptom resolution in patients with existing OA, 6% (n = 19) targeted OA disease-modifying therapeutics, and 5% (n = 16) targeted the prevention of OA in high-risk patients (P < .001). Primary interventions included medical devices (44%, n = 137), pharmaceutical drugs (14%, n = 42), surgical procedures (14%, n = 42), cellular biologics (13%, n = 41), and behavioral therapies (13%, n = 41). There was a significantly higher number of disease-modifying therapeutics for cellular biologics than pharmaceutical drugs (30% vs 14%) (P = .015). Most trials targeted the knee joint (63%, P = .042), with 38% of all trials evaluating joint arthroplasty. There were no significant differences between private sector and government funding sources (43% and 49%, respectively) (P = .288), yet there was a significantly lower rate of funding from industry (8%) (P = .026). CONCLUSIONS: There was a significantly higher number of clinical trials investigating symptomatic resolution therapy (89%) for existing OA in comparison to preventative (5%) and disease-modifying (6%) therapies. The most common interventions involved medical devices and joint replacement surgery, with the knee joint accounting for more than 60% of the current clinical trials for OA. There was a significantly higher number of disease-modifying therapeutics for cellular biologics than pharmaceutical drugs. Funding of clinical trials was split between the private sector and government, with a low rate of reported funding from industry partners. CLINICAL RELEVANCE: Identifying existing needs in the current market may help increase rates of research funding or optimize current funding pathways, in this study, specifically for targeting unaddressed focus areas in OA research. Our systematic review highlights the potential need for additional research and development regarding OA preventative and disease-modifying therapies.

Fibular Collateral Ligament Reconstruction Graft Options: Clinical and Radiographic Outcomes of Autograft Versus Allograft.

PURPOSE: To compare varus knee stability and clinical outcomes between patients who underwent fibular collateral ligament reconstruction (FCLR) or lateral collateral ligament (LCL) reconstruction with autografts versus allografts when undergoing concomitant anterior cruciate ligament reconstruction (ACLR). METHODS: All patients who underwent primary ACLR and concomitant FCLR from 2010 to 2017 performed by a single surgeon (R.F.L.) were retrospectively identified. Clinical characteristics and graft choices for FCLR were collected. Patients with a minimum 2-year follow-up for clinical outcome scores and 6-month stress radiographs were included. Patients with any other ligamentous procedure or revision ACLR were excluded. RESULTS: We identified 69 primary ACLR with concomitant FCLR patients who met the inclusion criteria. Fifty patients underwent FCLR with semitendinosus autografts, and 19 with allografts. There were no significant side-to-side differences (SSDs) in lateral compartment gapping on varus stress x-rays between the 2 cohorts (allograft, 0.49 mm; autograft, 0.15 mm, P = .22), and no FCLR failures. There were no significant differences between autograft and allograft groups at minimum 2-year outcomes for 12-Item Short Form mental or physical composite score (SF12 MCS, P = .134; SF12 PCS, P = .642), WOMAC total (P = .158), pain (P = .116), stiffness (P = .061), or activity (P = .252); International Knee Documentation Committee (IKDC) (P = .337), Tegner (P = .601), Lysholm (P = .622), or patient satisfaction (P = .218). There were no significant differences in clinical knee stability between groups at an average follow-up of 3.6 years (P = 1.0). CONCLUSION: There were no differences in varus stress laxity 6 months postoperatively or clinical outcome scores at ≥2 years postoperatively between patients having FCL reconstructions with either autograft or allograft. This study demonstrates that both hamstring autografts and allografts for FCL reconstructions offer reliable and similar radiographic and clinical results at short-term follow-up. LEVEL OF EVIDENCE: III, retrospective comparative trial.

The identification and treatment of snapping posterior tendons of the knee improves patient clinical outcomes.

PURPOSE: To assess the most common presenting symptoms, clinical outcomes, and patient satisfaction following treatment of either snapping medial pes anserinus hamstrings or snapping lateral biceps femoris tendons. METHODS: Consecutive patients with a minimum 2-year follow-up after isolated medial hamstring release for a diagnosis of medial snapping pes anserinus tendons or patients treated with primary biceps repair for lateral snapping biceps femoris tendons were evaluated. Clinical outcome scores of the following domains were collected: SF12, WOMAC score, Lysholm Knee Survey, and a simple numeric patient satisfaction score (0-10). Statistical analysis was performed with paired t-tests between preoperative and postoperative scores. RESULTS: At an average follow-up of 4.6 years (range 2.0-8.6 years) with two patients lost to follow-up, six consecutive patients (three male, three female) with seven knees were diagnosed with medial snapping pes anserinus tendons and treated with semitendinosus and gracilis tenotomies. Seven knees in seven patients (three male, four female) were diagnosed with lateral snapping biceps femoris tendons and were treated with an isolated biceps femoris repair. Nine of 13 patients were able to return to full desired activities/pre-operative level of sporting activities (4/6 medial, 5/7 lateral. Lysholm and SF-12 scores improved from preoperative to post-operative status for patients with snapping biceps femoris. Only patients undergoing primary biceps repair showed improvement across all WOMAC domains. Patients with medial hamstring tenotomy demonstrated improvement in Lysholm scores. Median postoperative satisfaction for both pathologies was 7 out of 10. CONCLUSION: Medial hamstring release for snapping pes anserinus and isolated biceps repair for lateral snapping biceps femoris yields improvement in patient satisfaction and clinical outcomes at mid-term follow-up. LEVEL OF EVIDENCE: IV.

Increased posterior tibial slope results in increased incidence of posterior lateral meniscal root tears in ACL reconstruction patients.

PURPOSE: While the association with acute anterior cruciate ligament (ACL) tears has been established, other risk factors and associated pathologies which occur with a concomitant lateral meniscal posterior root tear (LMPRT) are not well defined. The purpose of this study was to compare the risk factors and concomitant pathologies between patients with LMPRT and patients without LMPRTs in the setting of a primary ACL tear. METHODS: Patients with a LMPRT identified at the time of primary ACL reconstruction by a single surgeon were identified. These patients were matched by age and sex to patients undergoing primary ACL reconstruction who were not found to have lateral meniscus root tears (control group) in a 1:1 ratio. Lateral posterior tibial slope (PTS), medial PTS, lateral femoral condyle height and depth, lateral tibial plateau depth, and lateral tibial plateau subluxation were measured on MRI. Anteroposterior full-limb alignment radiographs were used to measure the medial proximal tibia angle (MPTA), the mechanical lateral distal femoral angle (mLDFA), and the mechanical weightbearing axis for the injured extremity. RESULTS: One-hundred three patients were included in both the LMPRT group and the matched control group. Patients with a LMPRT had a significantly steeper lateral PTS (9.1° vs. 7.0°, p = 0.001), a steeper medial PTS (7.0° vs. 6.0°, p = 0.03), and a greater lateral-to-medial slope asymmetry (2.0° vs. 1.0°, p = 0.001). There were no differences in lateral femoral condyle depth or height, lateral tibial plateau depth, lateral tibial plateau subluxation, MPTA, mLDFA, or mechanical weightbearing axis between groups. There was a significantly increased incidence of medial meniscus ramp lesions in patients with lateral meniscus posterior root tears compared with controls (34.0% vs. 15.5%, odds ratio: 2.8, p = 0.002). There were no associations with concomitant ligament injuries, medial meniscus root tears, or non-ramp tears based on case/control grouping. CONCLUSION: In conclusion, LMPRTs in the setting of primary ACL injuries were associated with significantly increased lateral and medial PTSs, and increased asymmetry between lateral and medial PTSs. In addition, clinicians should be aware of the increased incidence of concurrent medial meniscal ramp lesions in patients with LMPRTs. Knowledge of these associations helps guide clinical decision-making and counselling of patients in the setting of ACL tears with concomitant LMPRTs. LEVEL OF EVIDENCE: IV.

Risk Factors and Effect of Acute Kidney Injury on Outcomes Following Total Hip and Knee Arthroplasty.

BACKGROUND: Development of acute kidney injury (AKI) following primary total joint arthroplasty (TJA) is a potentially avoidable complication associated with negative outcomes including discharge to facilities and mortality. Few studies have identified modifiable risk factors or strategies that the surgeon may use to reduce this risk. METHODS: We identified all patients undergoing primary TJA at a single hospital from 2005 to 2017, and collected patient demographics, comorbidities, short-term outcomes, as well as perioperative laboratory results. We defined AKI as an increase in creatinine levels by 50% or 0.3 points. We compared demographics, comorbidities, and outcomes between patients who developed AKI and those who did not. Multivariate regressions identified the independent effect of AKI on outcomes. A stochastic gradient boosting model was constructed to predict AKI. RESULTS: In total, 814 (3.9%) of 20,800 patients developed AKI. AKI independently increased length of stay by 0.26 days (95% confidence interval [CI] 0.14-0.38, P < .001), in-hospital complication risk (odds ratio = 1.73, 95% CI 1.45-2.07, P < .001), and discharge to facility risk (odds ratio = 1.26, 95% CI 1.05-1.53, P = .012). Forty-one predictive variables were included in the predictive model, with important potentially modifiable variables including body mass index, perioperative hemoglobin levels, surgery duration, and operative fluids administered. The final predictive model demonstrated excellent performance with a c-statistic of 0.967. CONCLUSION: Our results confirm that AKI has adverse effects on outcome metrics including length of stay, discharge, and complications. Although many risk factors are nonmodifiable, maintaining adequate renal perfusion through optimizing preoperative hemoglobin, sufficient fluid resuscitation, and reducing blood loss, such as through the use of tranexamic acid, may aid in mitigating this risk.

Clinical Characteristics and Outcomes After Anatomic Reconstruction of the Proximal Tibiofibular Joint.

PURPOSE: To assess the most common presenting symptoms, clinical outcomes, and satisfaction after anatomic reconstruction of the proximal tibiofibular joint (PTFJ) with a free semitendinosus autograft. METHODS: Consecutive patients with minimum 2-year follow-up after isolated anatomic PTFJ reconstruction were retrospectively reviewed. Patients were evaluated with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and Lysholm Knee Survey score along with a simple numeric patient satisfaction score (0-10, with 10 rated as perfect). Statistical analysis was performed with paired t tests, with P < .05 considered significant. RESULTS: The study included 16 PTFJ reconstruction surgical procedures in 15 patients with isolated proximal tibiofibular instability verified by an examination under anesthesia (4 reconstructions in male patients vs 12 in female patients); the average age was 37.9 ± 14.6 years, with an average follow-up period of 43.2 months (range, 22-72 months). Of the 13 patients with complete follow-up, 11 (84.6%) were able to return to full desired activities and previous level of sport. Fourteen patients presented with concomitant common peroneal nerve pathology. Two patients had a subsequent complication. No patients needed an additional procedure. Significant (P < .05) improvement occurred across all WOMAC domains and in the WOMAC total score, from 31.4 (±14.9) preoperatively to 15.2 (±15.5) postoperatively. Lysholm Knee Survey scores significantly (P < .05) improved from 51.2 (±17.2) to 75.0 (±18.0). Patients' overall satisfaction was rated 7.6 (± 2.7) of 10. CONCLUSIONS: At an average follow-up of 43.2 months, anatomic PTFJ reconstruction for isolated PTFJ instability provided improvement in clinical outcomes, a return to activities, and a low risk of complications or need for additional procedures. CLINICAL RELEVANCE: PTFJ reconstruction with hamstring tendon graft is a promising surgical treatment that improves patient satisfaction when conservative treatment of PTFJ instability fails. LEVEL OF EVIDENCE: Level IV, case series.

Conversion of Failed Proximal Long Head of the Biceps Tenodesis to Distal Subpectoral Tenodesis: Outcomes in an Active Population.

PURPOSE: To assess failure rates and patient reported outcomes following revision of failed proximal long head of the biceps (LHB) tenodesis. METHODS: Patients from an active-military population who underwent revision proximal (suprapectoral) to distal (subpectoral) LHB tenodesis were prospectively enrolled. Patients were included if they were between the ages of 16 and 60 years presenting after a previous biceps tenodesis with mechanical failure and clinical failure, defined as Single Assessment Numeric Evaluation (SANE) or American Shoulder and Elbow Surgeons (ASES) <70. Exclusion criteria were concomitant rotator cuff repair or debridement, full-thickness rotator cuff tear, extensive labral tears, or any evidence of glenohumeral arthritis. Pre- and postoperative SANE and ASES were documented and analyzed. RESULTS: From 2004 to 2010, a total of 12 patients (all male) with a mean age of 39.9 years (range, 30-54 years) were assessed at a mean follow-up time of 29 months (range, 24-38 months). Nine patients presented with a failed tenodesis construct located at the top of the bicipital groove and 9 patients had LHB tendons originally affixed with an interference screw. Diagnostic arthroscopy revealed that the majority of patients (10/12) had excessive scarring at the site of previous fixation. Mean preoperative assessments of SANE (70.4) and ASES (59.9) improved postoperatively to SANE (90.3; P < .01) and ASES (89.8; P < .01). No patients were lost due to follow-up, and there were no reported complications or failures. All patients returned to full active duty and were able to perform all required physical tests before returning to their vocation. CONCLUSIONS: Patients presenting with symptoms following a proximal LHB tenodesis can be successfully converted to a distal (subpectoral) LHB tenodesis with favorable outcomes. Although in a small sample, there was excessive scarring and synovitis in a majority, which improved significantly when treated with a revision subpectoral tenodesis with minimal complication risk and no reported failures. LEVEL OF EVIDENCE: IV (Therapeutic case series).

Medial Patellotibial Ligament Reconstruction Improves Patella Tracking When Combined With Medial Patellofemoral Reconstruction: An In Vitro Kinematic Study.

PURPOSE: To investigate the isolated and combined effects of medial patellofemoral ligament (MPFL) and medial patellotibial ligament (MPTL) deficiency and reconstruction on patellofemoral kinematics. METHODS: Sixteen matched-paired female cadaveric knee specimens with a mean age of 53.5 years (range, 26-65) were tested in 5 conditions: (1) intact, (2) MPFL or MPTL cut, (3) MPFL and MPTL combined cut, (4) MPFL or MPTL reconstruction, and (5) MPFL and MPTL combined reconstruction. Dynamic testing allowed continuous analysis of kinematics from 0° to 90° of knee flexion. Knees were also tested statically using a lateral load of 45 N at 0°, 30°, 60°, and 90° of flexion. In both dynamic and static loading tests, a motion capture system detected patellar position for each testing state to distinguish changes in patellar kinematics. Random-intercepts linear mixed-effects models were used to compare patellar kinematics. RESULTS: The MPFL is the primary restraint to lateral translation of the patella at all knee flexion angles. MPTL deficiency alone did not create significant patella instability, but further increased instability when the MPFL was deficient. Isolated MPFL and combined reconstruction provided improved stability. Through full range of motion native patella tracking was best recreated with combined ligament reconstruction. CONCLUSIONS: The MPFL plays the greatest role in medial patellar stability, but the MPTL appears to have an influence on patella tracking. This study provides further understanding to the impact of the MPFL and MPTL on patellofemoral motion with implications for reconstruction to improve stability and optimize patellofemoral tracking. CLINICAL RELEVANCE: This study provides further understanding of the role of the MPFL and MPTL on patellofemoral motion with implications for reconstruction to improve stability and optimize patellofemoral tracking.

Influence of Medial Meniscus Bucket-Handle Repair in Setting of Anterior Cruciate Ligament Reconstruction on Tibiofemoral Contact Mechanics: A Biomechanical Study.

PURPOSE: To compare the impact of an inside-out repair versus meniscectomy of a medial meniscus bucket-handle tear in restoring native contact areas and pressures across the tibial plateaus in the setting of an anterior cruciate ligament (ACL) reconstruction (ACLR). METHODS: Ten fresh-frozen cadaveric knees were tested in 6 knee conditions (1: intact; 2: ACL torn and bucket-handle tear of medial meniscus, flipped; 3: bucket-handle tear of medial meniscus, reduced; 4: bucket-handle tear of medial meniscus, repaired via inside-out vertical mattress suture technique; 5: ACLR with bone patella tendon bone autograft and bucket-handle repair; 6: ACLR and medial meniscus bucket-handle tear debridement) at 4 flexion angles (0°, 30°, 45°, and 60°), under a 1,000-N axial load. Contact area and pressure were measured with Tekscan sensors. RESULTS: ACLR with a concurrent medial meniscectomy for a medial meniscus bucket-handle tear resulted in significantly decreased contact area (P < .05) and increased mean and peak pressure in both the medial and lateral compartments across all tested flexion angles (P < .05). The ACLR with medial meniscectomy state also demonstrated significantly lower contact area than the bucket-handle repair state between 30° and 60° of flexion (all P < .05). CONCLUSIONS: Resection of a bucket-handle medial meniscus tear concurrent with an ACLR resulted in significant increases in mean and peak contact pressures in not only the medial but also the lateral compartment. Preservation of the medial meniscus in the face of a bucket-handle tear is essential to more closely restore native tibiofemoral biomechanics. CLINICAL RELEVANCE: The increased mean and peak tibiofemoral contact pressure seen with excision of a bucket-handle medial meniscus tear would over time result in increased cartilaginous degradation and resultant osteoarthritis. Decreasing both of these factors through concomitant ACLR and inside-out bucket-handle meniscal repairs should improve patient outcomes by restoring knee biomechanics and kinematics closer to that of the native state.