Editorial Commentary: Bridging Graft Techniques Improve Short-Term Outcomes for Irreparable Rotator Cuff Tear Repair.

There is a growing need for nonarthroplasty treatment options for irreparable rotator cuff tears. Options include superior capsular reconstruction (SCR), tendon transfers, subacromial balloon spacer, bridge grafting, biological tuberoplasty, and partial rotator cuff repair with or without augmentation. In our experience, repair with marginal convergence techniques is superior to SCR; if there is enough tissue, repair is the preferred strategy. In an effort to improve outcomes after repair, there has been increased interest in the use of interposition or bridging graft (BG) techniques, in which an allograft or autograft is secured on the humerus laterally and to the remnant tendon medially. Interposition or bridging grafts can be used to supplement partial repair in an effort to replace the patient's own missing tissues, and restore the biomechanical force couple of the rotator cuff and create a humeral head-depressing spacer effect in the subacromial space. These techniques show promising results compared to superior capsular reconstruction. Various graft options for BG are available, including human dermal allograft, fascia lata autograft, and tenotomized biceps autograft. Multiple animal studies have demonstrated that interposition grafts can improve the biomechanical properties of the repair construct, and histological studies in animal models have shown evidence of tissue in-growth into the BG, which could lead to increased repair strength over time. Finally, recent studies suggest that a bridging graft may improve short-term outcomes compared to partial repair alone. It remains to be seen whether this difference is clinically meaningful and durable.

The Impact of Neurological Disorders on Clinical and Functional Outcomes after Shoulder Arthroplasty: A Systematic Review.

BACKGROUND: Patients with pre-existing neurologic disorders present a unique set of challenges for shoulder arthroplasty (SA) surgeons due to the presence of concomitant contractures, muscle weakness, and spasticity, which may affect outcomes and complication rates after shoulder arthroplasty. The goal of this systematic review was to evaluate the clinical and functional outcomes after SA in patients pre-existing with neurologic disorders, focusing on complication and reoperation rates. METHODS: This systematic review was performed in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines outlined by Cochrane Collaboration. A search of PubMed, the Medline Library, and EMBASE from inception until September 2023 was conducted to obtain studies reporting on outcomes after SA in patients with neurological disorders. Study demographics and information on outcomes including patient-reported outcomes and complication rates were collected. The methodological quality of included primary studies was appraised using the MINORS scoring system. RESULTS: Twenty articles published between 1997 and 2023 met inclusion criteria. In total, 13,126 patients with neurological conditions with 7 different neurological disorders (Parkinson's disease (PD), epilepsy and seizures, cerebral palsy (CP), poliomyelitis, Charcot neuropathy (CN), cerebrovascular disease (CVD) and multiple sclerosis (MS)) were included. The mean patient age was 64.3 years (range, 33.0 - 75.8 years), 51.4% of patients were male, and the mean postoperative follow-up time was 5.1 years (range, 1.4 - 9.9 years). PD was the most reported neurological disorder (9 studies, 8,033 patients), followed by epilepsy (4 studies, 3,783 patients), and MS (1 study, 1,077 patients). While these patients did experience improvements in outcomes following SA, high complication and revision rates were noted. CONCLUSIONS: Patients with neurologic disorders demonstrate improvements in pain and function after SA but have higher reported complication and revision rates when compared with patients without neurologic conditions. This systematic review offers valuable data for both the surgeon and patient regarding anticipated clinical results and possible complications from SA in patients with neurologic disorders that may aid in shared decision-making when considering SA.

Assessment of fatty infiltration of the hamstring muscles in chronic proximal hamstring ruptures and effect on clinical outcomes after surgical repair: a novel application of the Goutallier classification.

INTRODUCTION: Increased time to surgery has been previously associated with poorer clinical outcomes after surgical treatment of proximal hamstring ruptures, though the etiology remains unclear. The purpose of this study was to evaluate whether degree of muscle atrophy, as assessed using the Goutallier classification system, is associated with worse outcomes following surgical treatment of chronic proximal hamstring ruptures. MATERIALS AND METHODS: This was a retrospective case series of patients who underwent repair of proximal hamstring ruptures from 2012 to 2020 with minimum 2-year follow-up. Patients were included if they underwent primary repair of a proximal hamstring rupture ≥ 6 weeks after the date of injury and had accessible preoperative magnetic resonance imaging (MRI). Exclusion criteria were allograft reconstruction, endoscopic repair, or prior ipsilateral hip surgery. Patients were administered validated surveys: the modified Harris Hip Score (mHHS) and Perth Hamstring Assessment Tool (PHAT). Fatty atrophy on preoperative MRI was independently graded by two musculoskeletal radiologists using the Goutallier classification. Multivariate regression analysis was performed to evaluate associations of preoperative characteristics with muscle atrophy, as well as mHHS and PHAT scores. RESULTS: Complete data sets were obtained for 27 patients. A majority of this cohort was male (63.0%), with a mean age of 51.5 ± 11.8 years and BMI of 26.3 ± 3.8. The mean follow-up time was 62.6 ± 23.1 months, and the mean time from injury-to-surgery was 20.4 ± 15.3 weeks. The Goutallier grading inter-reader weighted kappa coefficient was 0.655. Regression analysis demonstrated that atrophy was not significantly associated with PHAT (p = 0.542) or mHHS (p = 0.574) at latest follow-up. Increased age was significantly predictive of muscle atrophy (ß = 0.62, p = 0.005) and was also found to be a significant predictor of poorer mHHS (ß = - 0.75; p = 0.037). CONCLUSIONS: The degree of atrophy was not found to be an independent predictor of clinical outcomes following repair of chronic proximal hamstring ruptures. Increasing age was significantly predictive of increased atrophy and poorer patient-reported outcomes.

Concentration of synovial fluid biomarkers on the day of anterior cruciate ligament (ACL)-reconstruction predict size and depth of cartilage lesions on 5-year follow-up.

PURPOSE: The current investigation evaluated the relationship between the synovial fluid cytokine microenvironment at the time of isolated anterior cruciate ligament (ACL) reconstruction and the presence of subsequent chondral wear and radiologic evidence of osteoarthritis (OA) on cartilage-specific MRI sequences at a minimum of 5-year follow-up. METHODS: Patients who underwent primary ACL reconstruction with no baseline concomitant cartilage or meniscal defects and had synovial fluid samples obtained at the time of surgery were retrospectively identified. Patients with a minimum of 5 years of postoperative follow-up were contacted and asked to complete patient-reported outcome (PRO) measures including Visual Analog Scale (VAS) for pain, Lysholm Scale, Knee Injury and Osteoarthritis Outcome Score (KOOS), and Tegner Activity Scale, along with postoperative magnetic resonance imaging (MRI). The concentration of ten biomarkers that have previously been suggested to play a role in cartilage degradation and inflammation in the joint space was measured. Linear regression controlling for age, sex, and body mass index (BMI) was performed to create a model using the synovial fluid concentrations at the time of surgery to predict postoperative semiquantitative cartilage lesion size and depth on MRI at a minimum of 5 years follow up. RESULTS: The patients were comprised of eight males (44.4%) and ten females (55.6%) with a mean age at the time of surgery of 30.8 ± 8.7 years (range 18.2-44.5 years). The mean follow-up time was 7.8 ± 1.5 years post-operatively (range 5.7-9.7 years). MCP-1, VEGF, and IL-1Ra were found to have significant associations with the presence of postoperative cartilage wear (p < 0.05). No correlations were demonstrated among the biomarker concentrations at the time of injury with PRO scores at final follow-up (NS). CONCLUSION: Synovial fluid inflammatory biomarker concentrations at the time of injury can predict progression of early-stage post-traumatic osteoarthritis at a mean of almost 8 years post-operatively. Findings from this study may help identify treatment targets to alter the natural history of cartilage loss following anterior cruciate ligament injury. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

No difference in clinical outcomes between operative and nonoperative management of minimally retracted proximal hamstring ruptures.

PURPOSE: The indications for surgical treatment of proximal hamstring ruptures are continuing to be refined. The purpose of this study was to compare patient-reported outcomes (PROs) between patients who underwent operative or nonoperative management of proximal hamstring ruptures. METHODS: A retrospective review of the electronic medical record identified all patients who were treated for a proximal hamstring rupture at our institution from 2013 to 2020. Patients were stratified into two groups, nonoperative or operative management, which were matched in a 2:1 ratio based on demographics (age, gender, and body mass index), chronicity of the injury, tendon retraction, and number of tendons torn. All patients completed a series of PROs including the Perth Hamstring Assessment Tool (PHAT), Visual Analogue Scale for pain (VAS), and the Tegner Activity Scale. Statistical analysis was performed using multi-variable linear regression and Mann-Whitney testing to compare nonparametric groups. RESULTS: Fifty-four patients (mean age = 49.6 ± 12.9 years; median: 49.1; range: 19-73) with proximal hamstring ruptures treated nonoperatively were successfully matched 2:1 to 27 patients who had underwent primary surgical repair. There were no differences in PROs between the nonoperative and operative cohorts (n.s.). Chronicity of the injury and older age correlated with significantly worse PROs across the entire cohort (p < 0.05). CONCLUSIONS: In this cohort of primarily middle-aged patients with proximal hamstring ruptures with less than three centimeters of tendon retraction, there was no difference in patient-reported outcome scores between matched cohorts of operatively and nonoperatively managed injuries. LEVEL OF EVIDENCE: Level III.

Increased time from injury to surgical repair in patients with proximal hamstring ruptures is associated with worse clinical outcomes at mid-term follow-up.

INTRODUCTION: Prior studies of hamstring tendon tears have reported varied findings on whether increased delay from injury to surgery is associated with worse outcomes. The purpose of this study was to determine whether increased time from injury to surgical repair is associated with worse clinical outcomes in patients with proximal hamstring ruptures. MATERIALS AND METHODS: Patients who underwent surgical repair of a proximal hamstring rupture from 2010 to 2019 were followed for a minimum of 24 months from surgery. A cutoff of 6 weeks from injury to the time of surgery was used to distinguish between acute and chronic ruptures. All patients completed patient-reported outcome measures (PROs) at the final follow-up. Multiple factors were analyzed for their effects on PROs including time to surgery, amount of tendon retraction, and demographics such as sex and age. RESULTS: Complete data sets were obtained for 38 patients at a mean follow-up of 4.9 years. All data is reported as a mean ± standard deviation. Patients who underwent acute repair of proximal hamstring ruptures had significantly greater Perth Hamstring Assessment Tool (PHAT) scores than those who underwent chronic repair (76.9 ± 18.8 vs 60.6 ± 18.2, p = 0.01). Increased time to surgery was significantly correlated with worse PHAT scores (ρ = - 0.47, p = 0.003). There was no difference in PROs based on the amount of tendon retraction, number of tendons torn, sex, smoking status, or BMI. CONCLUSIONS: This study found that acute repair performed within 6 weeks of injury appears to yield improved PROs compared to chronic repair. These data highlight the importance of timely and accurate diagnosis of proximal hamstring ruptures and early operative intervention for surgical candidates.

Surgical Considerations in Revision Anterior Cruciate Ligament Reconstruction.

Revision anterior cruciate ligament reconstruction (rACLR) procedures are often technically and intellectually challenging. However, with careful preoperative evaluation and planning, the likelihood of success can be maximized. Understanding the various etiologies of and contributors to primary ACLR failure can guide the surgical plan in terms of whether concomitant procedures are needed. Although successful outcomes have been reported with both one-stage and two-stage rACLRs, appropriate patient selection is important. Overall, clinical outcomes including patient-reported outcomes, graft failure rates, and return to sport are worse after rACLR compared with primary ACLR. It is important to review the preoperative evaluation, surgical considerations, and outcomes of rACLR.

Knotted Versus Knotless Anchors for Labral Repair in the Shoulder: A Systematic Review.

PURPOSE: To compare biomechanical and clinical outcomes between knotless and knotted anchors in arthroscopic labral repair, specifically in (1) Bankart repair, (2) SLAP repair, (3) posterior labral repair, and (4) remplissage augmentation of Bankart repair. METHODS: MEDLINE, EMBASE, and the Cochrane Library were searched according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to find biomechanical and clinical studies comparing knotted and knotless anchors using the search term "knotless anchor." RESULTS: Overall, 17 studies met inclusion criteria. There were 7 studies evaluating the biomechanical outcomes, of which 5 found mixed results between knotted and knotless anchors for arthroscopic Bankart repair, 1 demonstrated a difference for SLAP repair favoring knotless anchors, and 2 showed no significant difference for Remplissage in terms of ultimate load-to-failure. Four studies evaluated knotless labral anchors compared with knotted anchors in patients undergoing arthroscopic Bankart repair with no significant differences in outcomes reported between the 2 anchor types, except in one study that found an improved visual analog scale score and a lower recurrence and revision rate with knotted anchors. Five studies evaluated knotless anchors compared with knotted anchors in patients undergoing SLAP repair, and none of the included studies found any significant differences in the patient reported outcome measures or revision rates. Of the 5 studies comparing operative time, 4 found a reduced time with knotless anchors. CONCLUSIONS: The clinical results show no significant differences in outcomes between knotless and knotted anchors for labral repair in the shoulder, including Bankart repair, SLAP repair, and posterior labral repair. However, there was conflicting evidence supporting knotless or knotted anchors in the biomechanical studies. However, operative times may be reduced with the use of knotless anchors. LEVEL OF EVIDENCE: III, A Systematic Review of Level II and III studies.

Concomitant periarticular fractures predict worse patient-reported outcomes in multiligament knee injuries: a matched cohort study.

AIM: There is a shortage of high-level evidence regarding periarticular fractures affect outcomes after MLKIs. The purpose of this study was to determine whether concomitant periarticular fractures with mutliligament knee injuries (MLKIs) predict worse patient-reported outcomes (PROMs) when compared to MLKIs without concomitant periarticular fractures after surgical repair and/or reconstruction. MATERIALS AND METHODS: Medical records of patients who sustained MLKIs from January 1, 2009 to June 1, 2014 were retrospectively reviewed. All patients aged 18-65 years with grade III injuries of two or more knee ligaments and 1-year minimum follow-up were included. Patients with injuries or surgeries to either knee before their MLKIs were excluded. Radiographs and computed tomography imaging obtained at the time of injury were used to detect concomitant periarticular fractures. Patients with and without concomitant periarticular fractures were matched on a 1:2 basis, respectively. Multiple PROMs were collected, including the IKDC Subjective Knee Form (IKDC-SKF), and Knee Injury and Osteoarthritis Outcome Score (KOOS). The independent t-test was used to compare PROMs between patients with and without periarticular fractures. RESULTS: Eighteen patients (10 males, 8 females) with a mean follow-up of 4.0 years (range 1.1-8.6 years) were included in the final analysis, with six patients having MLKIs and concomitant periarticular fractures. Compared to patients with isolated ligamentous MLKIs (n = 12), patients with concomitant periarticular fracture (n = 6) demonstrated significantly worse outcomes on the IKDC-SKF (54.2 ± 13.3 vs. 74.0 ± 19.6, p = 0.04) and KOOS-Sports and Recreation subscale (41.2 ± 32.4 vs. 70.8 ± 19.4, p = 0.03). CONCLUSION: The presence of a periarticular fracture predicted significantly worse clinical outcomes in the setting of MLKI. These findings may be useful in determining the prognosis of MLKI with concomitant periarticular fractures treated with surgical repair and/or reconstruction.

Management of Concomitant Preoperative Rotator Cuff Pathology and Adhesive Capsulitis: A Systematic Review of Indications, Treatment Approaches, and Outcomes.

PURPOSE: Concomitant preoperative adhesive capsulitis (AC) and rotator cuff (RC) pathology pose therapeutic challenges in light of contrasting interventional and rehabilitative goals. The purposes of this systematic review were to assess the literature regarding the management and rehabilitation of patients with concomitant RC tears and preoperative AC and to compare overall clinical outcomes between strategies for this common scenario. METHODS: In accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, 3 databases (MEDLINE, Embase, and PubMed) were searched and screened in duplicate using predetermined criteria for studies on the aforementioned patient population. Descriptive statistics are presented. RESULTS: Of 952 studies, 17 involving 662 shoulders, with a mean age of 59.6 ± 3.5 years, 57.9% female patients, and a mean follow-up period of 18.6 months, were included. Capsular release (CR) (86.1%) and manipulation under anesthesia (MUA) (33.1%) were the most common co-interventions with RC repair. Across studies, mean preoperative American Shoulder and Elbow Surgeons scores ranged from 29.0 to 61.3, visual analog scale scores (pain) ranged from 5.3 to 8.0, and Constant scores ranged from 18.0 to 48.0. Mean postoperative American Shoulder and Elbow Surgeons scores ranged from 76.9 to 92.0, visual analog scale scores (pain) ranged from 0.3 to 2.5, and Constant scores ranged from 72.6 to 93.2. Postoperative rehabilitation comprised abduction braces and passive range of motion immediately postoperatively for mean durations of 5.0 weeks and 5.3 weeks, respectively, followed by active range of motion at a mean of 5.3 weeks and strengthening at 10.9 weeks. Postoperative complications included stiffness, RC retear, instability, glenoid fracture, and superficial infection. CONCLUSIONS: The results of this systematic review support treatment of patients with degenerative RC tears and concomitant AC with a combination of RC repair and MUA, CR, or both MUA and CR. Regardless of the treatment modality, accelerated postoperative rehabilitative protocols are beneficial in preventing postoperative persistence of AC and can be safely used in this scenario without a substantial increase in complication rates compared with patients undergoing RC repair alone with conservative rehabilitation. LEVEL OF EVIDENCE: Level V, systematic review of Level II, III, IV, and V studies.

Radiographic images are inapplicable for a precise evaluation of the femoral tunnel position following MPFL reconstruction.

PURPOSE: In medial patellofemoral ligament (MPFL) reconstruction, it remains controversial whether more accurate femoral tunnel positioning is correlated with improved clinical outcomes. The purpose was to verify the accuracy of methods for evaluating tunnel positioning, one of which is the use of postoperative radiographs, in determining the femoral tunnel position following MPFL reconstruction and to compare the variability of tunnel positions to the intraoperatively documented positions on a true-lateral view. METHODS: Seventy-three consecutive MPFL reconstructions were prospectively enrolled. Femoral tunnel positions were intraoperatively determined using fluoroscopy to obtain true-lateral radiographs. Postoperatively, lateral radiographic images were taken. Seven independent radiologists and seven independent orthopaedic knee surgeons evaluated the femoral tunnel position and amount of malrotation for each radiograph. Deviations from the Schoettle's point were measured and repeated after 4 weeks. Intraobserver and interobserver analyses of variance were calculated to determine the reliability of measurements on both intraoperative and postoperative radiographs. RESULTS: Fifty-six patients were included in the final analysis. Tunnel positions were unable to be identified on postoperative radiographs in 14% of cases on average, independent of the degree of radiograph rotation. Intraoperative images showed mean deviations from the tunnel position to the centre of Schoettle's point of 1.9 ± 1.4 mm and 1.6 ± 1.0 mm in anterior-posterior and proximal-distal direction, respectively. Postoperative radiographs showed mean anterior-posterior and deviations of 7.4 ± 4.4 mm and 8.9 ± 5.8 mm assessed by orthopaedic surgeons and 10.6 ± 6.3 mm and 11.6 ± 7.1 mm assessed by radiologists at first and repeated measurement, respectively. The mean proximal-distal deviations were 4.8 ± 4.4 mm and 6.5 ± 6.0 mm and 7.2 ± 6.3 mm and 8.1 ± 7.1 mm, respectively. Measurement of tunnel position on intraoperative fluoroscopic images was significantly different compared to postoperative radiographs for each of the 14 observers (p < 0.05). Significant intraobserver and interobserver differences between the first and repeat measurements for both orthopaedic surgeons and radiologists were observed (p < 0.05). CONCLUSION: Measurement of the femoral tunnel position on postoperative lateral radiographs is not an accurate or reliable method for evaluating tunnel position after MPFL reconstruction due to exposure, contrast, and malrotation of the radiograph from a true-lateral image. In contrast, intraoperative fluoroscopic control allows for a precise lateral view and correct tunnel positioning. Thus, postoperative radiographic images may be unnecessary for the evaluation of femoral tunnel positions, particularly when intraoperative fluoroscopy has been used. STUDY DESIGN: Level II, prospective cohort study.

No difference between full thickness and partial thickness quadriceps tendon autografts in anterior cruciate ligament reconstruction: a systematic review.

PURPOSE: The purpose of this review was to compare outcomes and complication profiles of anterior cruciate ligament reconstruction (ACL-R) between full thickness (FT-Q) and partial thickness (PT-Q) quadriceps tendon (QT) autografts. METHODS: As per PRISMA guidelines, PubMed, EMBASE, and MEDLINE were searched in September 2017 for English language, human studies of all levels of evidence on patients undergoing primary ACL-R with FT-Q or PT-Q. This search was repeated in March 2018 to capture additional articles. Data regarding postoperative outcomes and complications were abstracted. Due to heterogeneous reporting, data were not combined in meta-analysis and were summarized descriptively. RESULTS: Upon screening 3670 titles, 18 studies satisfied inclusion/exclusion criteria. The second search identified an additional two studies for a total of 20 studies (50% case-control, 50% case series). These studies examined 1212 patients (1219 knees) of mean age 29.8 years (range 15-59) followed a mean of 42.2 months (range 12-120). FT-Q and PT-Q autografts were used in eight studies (50.5% of knees), and thirteen studies (49.5% of knees), respectively. Only one study directly compared FT-Q to PT-Q. Instrumented laxity was less than 3 mm in 74.8 and 72.4% of the FT-Q and PT-Q groups, respectively. Postoperative IKDC Subjective Knee Form scores were similar between the FT-Q (82.5) and PT-Q (82.1) groups. Postoperative quadriceps strength, measured as a percentage of the contralateral side, were similar in the FT-Q (89.5%) and PT-Q (85.1%) groups. Graft failure rates for the FT-Q and PT-Q groups were 3.7 and 3.0%, respectively. CONCLUSION: Across the 20 studies included in this review, there appeared to be no difference in outcomes or complications between either FT-Q or PT-Q in primary ACL-R. Moreover, primary ACL-R using QT autografts appears to have successful outcomes with a low rate of graft failure, irrespective of tendon thickness. While further comparative studies are needed to better delineate the optimal thickness of quadriceps tendon for primary ACL-R, these data suggest that, in primary ACL-R, either FT-Q or PT-Q is efficacious and, in the clinical setting, surgeons may be justified in using either graft thickness. LEVEL OF EVIDENCE: IV, Systematic Review of Level III and IV studies.

Distal femur morphology affects rotatory knee instability in patients with anterior cruciate ligament ruptures.

PURPOSE: Distal femur morphology has been shown to influence knee joint kinematics and may affect rotatory knee laxity. The purpose of this study was to determine the relationship between rotatory knee laxity and distal femoral morphology in patients with complete anterior cruciate ligament (ACL) rupture. It was hypothesized that increased posterior femoral condylar depth on standard lateral radiographs, quantified as the "lateral femoral condyle ratio" would correlate with increased rotatory knee laxity, measured by a quantitative pivot shift test. METHODS: Consecutive patients who underwent ACL reconstruction from 2014 to 2016 were retrospectively reviewed. A standardized pivot shift test was performed preoperatively on both knees and quantified using tablet technology. Using standard lateral radiographs of the knee, the ratio of posterior condylar distance over total condylar distance was defined as the lateral femoral condyle ratio. RESULTS: Data sets were obtained for 57 patients. The mean anterior translation of the lateral knee compartment during a quantitative pivot shift test was found to be 4.0 ± 2.4 mm and 1.3 ± 0.9 mm for the injured and uninjured knees, respectively. The mean lateral femoral condyle ratio on X-ray was 63.2 ± 4.5%. There were significant correlations between the lateral femoral condyle ratio and the absolute quantitative (ρ = 0.370, p < 0.05) and side-to-side differences in anterior translation of the lateral knee compartment (ρ = 0.419, p < 0.05). CONCLUSION: The most important finding from this study is that increased posterior femoral condylar depth, quantified as a lateral femoral condyle ratio, is associated with increased rotatory knee laxity in ACL-deficient patients. This suggests that distal femur morphology may influence rotatory knee laxity. This study may assist clinicians in evaluating ACL injuries and identifying patients at greater risk for persistent increased rotatory knee laxity after ACL reconstruction. LEVEL OF EVIDENCE: III.

Fibroblast Growth Factor 9 Regulation by MicroRNAs Controls Lung Development and Links DICER1 Loss to the Pathogenesis of Pleuropulmonary Blastoma.

Pleuropulmonary Blastoma (PPB) is the primary neoplastic manifestation of a pediatric cancer predisposition syndrome that is associated with several diseases including cystic nephroma, Wilms tumor, neuroblastoma, rhabdomyosarcoma, medulloblastoma, and ovarian Sertoli-Leydig cell tumor. The primary pathology of PPB, epithelial cysts with stromal hyperplasia and risk for progression to a complex primitive sarcoma, is associated with familial heterozygosity and lesion-associated epithelial loss-of-heterozygosity of DICER1. It has been hypothesized that loss of heterozygosity of DICER1 in lung epithelium is a non-cell autonomous etiology of PPB and a critical pathway that regulates lung development; however, there are no known direct targets of epithelial microRNAs (miRNAs) in the lung. Fibroblast Growth Factor 9 (FGF9) is expressed in the mesothelium and epithelium during lung development and primarily functions to regulate lung mesenchyme; however, there are no known mechanisms that regulate FGF9 expression during lung development. Using mouse genetics and molecular phenotyping of human PPB tissue, we show that FGF9 is overexpressed in lung epithelium in the initial multicystic stage of Type I PPB and that in mice lacking epithelial Dicer1, or induced to overexpress epithelial Fgf9, increased Fgf9 expression results in pulmonary mesenchymal hyperplasia and a multicystic architecture that is histologically and molecularly indistinguishable from Type I PPB. We further show that miR-140 is expressed in lung epithelium, regulates epithelial Fgf9 expression, and regulates pseudoglandular stages of lung development. These studies identify an essential miRNA-FGF9 pathway for lung development and a non-cell autonomous signaling mechanism that contributes to the mesenchymal hyperplasia that is characteristic of Type I PPB.

The Use of Fluoroscopy Leads to Improved Identification of the Femoral Lateral Collateral Ligament Origin Site When Compared With Traditional Tactile Techniques.

PURPOSE: To determine whether a fluoroscopic technique can be used to improve the accuracy of the determination of the femoral origin of the lateral collateral ligament (LCL). METHODS: A 1-cm incision was made over the lateral epicondyle in 13 fresh-frozen cadaveric knee specimens, and the LCL origin was determined first by palpation and then with a previously described fluoroscopic method. Both points for the LCL origin were marked with 2-mm Kirschner wires. The distances between the center of the anatomic LCL origin and the LCL origin points determined by palpation and fluoroscopic imaging were calculated. An independent t-test was used to compare the distances between the anatomic LCL origin center and the determined LCL origin points. RESULTS: The LCL origin points determined by fluoroscopic imaging were significantly (P = .005) closer to the anatomic center of the LCL origin point than the ones determined by palpation (3.2 mm ± 1.6 mm vs 5.0 mm ± 1.6 mm, respectively). A total of 92.7% fluoroscopically determined LCL origin points were within a 5 mm radius surrounding the anatomic LCL origin point. In contrast, only 53.8% LCL origin points determined by palpation were within a 5 mm radius surrounding the anatomic LCL origin point. CONCLUSIONS: The use of palpation to identify the LCL origin may not be an accurate method for performing an isometric and anatomic LCL reconstruction. The use of fluoroscopic imaging appears to be a feasible method for identifying the LCL origin in clinical practice and may increase the accuracy of LCL origin identification. Fluoroscopic guidance improves accuracy in determining the anatomic LCL origin, which may help avoiding tunnel malplacement during LCL reconstruction. CLINICAL RELEVANCE: The use of a previously described radiographic method for identifying the LCL origin may be used to achieve a more anatomic LCL reconstruction.

Female sex is associated with greater rotatory knee laxity in collegiate athletes.

PURPOSE/HYPOTHESIS: The purpose of this observational study was to determine which factors, including sex, are associated with increased rotatory knee laxity in collegiate athletes with no history of knee injuries. It was hypothesized that increased rotatory knee laxity, measured by a quantitative pivot shift test, would correlate with female sex, increased anterior translation during the Lachman test, generalized ligamentous laxity, and knee hyperextension. METHODS: Ninety-eight collegiate athletes with a median age of 20 (range 18-25) years with no history of knee injuries were tested. IKDC and Marx activity scores were obtained and subjects underwent measurement of anterior translation during the Lachman test with a Rolimeter and measurement of knee hyperextension with a goniometer for both knees. A standardized pivot shift test was performed in both knees and quantified using image analysis technology. Generalized ligamentous laxity was assessed using the modified Beighton score. RESULTS: The average anterior translation of the lateral compartment during the pivot shift test was 1.6 mm (range 0.1-7.1) with a mean side-to-side difference of 0.6 mm (range 0-2.7). The average anterior translation during the Lachman test was 9.0 (range 2-15). The anterior translation of the lateral compartment during the pivot shift test was significantly higher in females (median, 1.6; range 0.3-4.9) than in males (1.1, 0.1-7.1 mm) (p < 0.05). Anterior translation of the lateral compartment during the pivot shift test was significantly correlated with anterior translation during the Lachman test (r = 0.34; p < 0.05). There was no significant correlation between anterior translation of the lateral compartment during the pivot shift test and knee hyperextension or modified Beighton score (n.s). CONCLUSION: The data from this study show that female sex is associated with increased rotatory knee laxity measured during the pivot shift test and anterior translation during the Lachman test in collegiate athletes. In the future, these data may be helpful in diagnosing and managing ACL injuries in athletes and could be used in the clinic as a baseline by which to compare and identify patients who might exhibit increased rotatory laxity. LEVEL OF EVIDENCE: Diagnostic level II.

Lateral femoral notch depth is not associated with increased rotatory instability in ACL-injured knees: a quantitative pivot shift analysis.

PURPOSE: A deep lateral femoral notch (LFN) on lateral radiographs is indicative of ACL injury. Prior studies have suggested that a deep LFN may also be a sign of persistent rotatory instability and a concomitant lateral meniscus tear. Therefore, the purpose of this study was to evaluate the relationship between LFN depth and both quantitative measures of rotatory knee instability and the incidence of lateral meniscus tears. It was hypothesized that greater LFN depth would be correlated with increased rotatory instability, quantified by lateral compartment translation and tibial acceleration during a quantitative pivot shift test, and incidence of lateral meniscus tears. METHODS: ACL-injured patients enrolled in a prospective ACL registry from 2014 to 2016 were analyzed. To limit confounders, patients were only included if they had primary ACL tears, no concurrent ligamentous or bony injuries requiring operative treatment, and no previous knee injuries or surgeries to either knee. Eighty-four patients were included in the final analysis. A standardized quantitative pivot shift test was performed pre-operatively under anesthesia in both knees, and rotatory instability, specifically lateral compartment translation and tibial acceleration, was quantified using tablet image analysis software and accelerometer sensors. Standard lateral radiographs and sagittal magnetic resonance images (MRI) of the injured knee were evaluated for LFN depth. RESULTS: There were no significant correlations between LFN depth on either imaging modality and ipsilateral lateral compartment translation or tibial acceleration during a quantitative pivot shift test or side-to-side differences in these measurements. Patients with lateral meniscus tears were found to have significantly greater LFN depths than those without on conventional radiograph and MRI (1.0 vs. 0.6 mm, p < 0.05; 1.2 vs. 0.8 mm, p < 0.05, respectively). CONCLUSION: There was no correlation between lateral femoral notch depth on conventional radiographs or MRI and quantitative measures of rotatory instability. Concomitant lateral meniscus injury was associated with significantly greater LFN depth. Based on these findings, LFN depth should not be used as an indicator of excessive rotatory instability, but may be an indicator of lateral meniscus injury in ACL-injured patients. LEVEL OF EVIDENCE: Prognostic level IV.

Increased medial and lateral tibial posterior slopes are independent risk factors for graft failure following ACL reconstruction.

PURPOSE: To analyze the contribution of increased lateral (LTPS) and medial tibial slopes (MTPS) as independent risk factors of graft failure following anterior cruciate ligament (ACL) reconstruction. MATERIALS AND METHODS: Fifty-seven patients with graft failure after ACL reconstruction who underwent revision surgery between 2009 and 2014 were enrolled and matched to a control group of 69 patients with primary anatomic successful ACL reconstruction. Patients were matched based on age, sex, date of primary surgery and graft type. LTPS and MTPS were measured on MRI in a blinded fashion. Tibial and femoral tunnel positions were determined on CT scans. Independent t test was used to compare the MTPS and LTPS between subgroups. Risks of graft failure associated with an increasing MTPS and LTPS were analyzed using binary logistic analysis. RESULTS: The means of LTPS (7.3°) and MTPS (6.7°) in the graft failure group were found to be significantly greater than in the control group (4.6° and 4.1°, respectively; p = < 0.001). Non-anatomic and anatomic tunnel positions were found in 42 cases (73.7%) and 15 cases (26.3%), respectively. There were no significant differences in MTPS or LTPS between patients with anatomic and non-anatomic tunnel positions within the graft failure group. An increase of the MTPS of 1° was associated with an 1.24 times increased likelihood of exhibiting graft failure [95% CI 1.07-1.43] (p = 0.003) and an increase of the LTPS of 1° was associated with an 1.17 times increased likelihood of exhibiting graft failure [95% CI 1.04-1.31] (p = 0.009). The increased risk was most evident in patients with a lateral tibial posterior slope of ≥ 10°. CONCLUSIONS: Increased LTPS and MTPS are independent risk factors for graft failure following ACL reconstruction regardless whether tunnel position is anatomic or non-anatomic. This information may be helpful to clinicians when considering slope correction in selected revision ACL reconstruction procedures.

Differences between traumatic and non-traumatic causes of ACL revision surgery.

PURPOSE: The purpose of this study was to evaluate and classify causes for anterior cruciate ligament (ACL) reconstruction failure. It was hypothesized that specific technical and biological reconstruction aspects would differ when comparing traumatic and non-traumatic ACL reconstruction failures. MATERIALS AND METHODS: One hundred and forty-seven consecutive patients who experienced ACL reconstruction failure and underwent revision between 2009 and 2014 were analyzed. Based on a systematic failure analysis, including evaluation of technical information on primary ACL reconstruction and radiological assessment of tunnel positions, causes were classified into traumatic and non-traumatic mechanisms of failure; non-traumatic mechanisms were further sub-divided into technical and biologic causes. Spearman's rank correlation coefficient and chi-squared tests were performed to determine differences between groups based on various factors including graft choice, fixation technique, technique of femoral tunnel positioning, tunnel malpositioning, and time to revision. RESULTS: Non-traumatic, i.e., technical, and traumatic mechanisms of ACL reconstruction failure were found in 64.5 and 29.1% of patients, respectively. Biological failure was found only in 6.4% of patients. Non-anatomical femoral tunnel positioning was found the most common cause (83.1%) for technical reconstruction failure followed by non-anatomical tibial tunnel positioning (45.1%). There were strong correlations between non-traumatic technical failure and femoral tunnel malpositioning, transtibial femoral tunnel drilling techniques, femoral transfixation techniques as well as earlier graft failure (p < 0.05). CONCLUSIONS: Technical causes, particularly tunnel malpositioning, were significantly correlated with increased incidence of non-traumatic ACL reconstruction failure. Transtibial femoral tunnel positioning techniques and femoral transfixation techniques, showed an increased incidence of non-traumatic, earlier graft failure.

High non-anatomic tunnel position rates in ACL reconstruction failure using both transtibial and anteromedial tunnel drilling techniques.

INTRODUCTION: Although it is well known from cadaveric and biomechanical studies that transtibial femoral tunnel (TT) positioning techniques are associated with non-anatomic tunnel positions, controversial data exist as so far no clinical differences could have been found, comparing transtibial with anteromedial techniques (AM). The purpose of the study was to analyze if graft failure following TT ACL reconstruction was more commonly associated with non-anatomic tunnel position in comparison with the AM technique. We hypothesized that, compared to AM techniques, non-anatomic tunnel positions correlate with TT tunnel positioning techniques. MATERIALS AND METHODS: A total of 147 cases of ACL revision surgery were analyzed retrospectively. Primary ACL reconstructions were analyzed regarding the femoral tunnel drilling technique. Femoral and tibial tunnel positions were determined on CT scans using validated radiographic measurement methods. Correlation analysis was performed to determine differences between TT and AM techniques. RESULTS: A total of 101 cases were included, of whom 64 (63.4%) underwent the TT technique and 37 (36.6%) the AM technique for primary ACL reconstruction. Non-anatomic femoral tunnel positions were found in 77.2% and non-anatomical tibial tunnel positions in 40.1%. No correlations were found comparing tunnel positions in TT and AM techniques, revealing non-anatomic femoral tunnel positions in 79.7 and 73% and non-anatomic tibial tunnel positions in 43.7 and 35.1%, respectively (p > 0.05). CONCLUSIONS: Considerable rates of non-anatomic femoral and tibial tunnel positions were found in ACL revisions with both transtibial and anteromedial femoral drilling techniques. Despite the potential of placing tunnels more anatomically using an additional AM portal, this technique does not ensure anatomic tunnel positioning. Consequently, the data highlight the importance of anatomic tunnel positioning in primary ACL reconstruction, regardless of the applied drilling technique.