Managing the Severe Cavus Foot Deformity in Global Humanitarian Programs.

The cavus foot represents a complex spectrum of deformity ranging from the subtle idiopathic to the severe sensorimotor neuropathy and other neuromuscular deformities. The successful surgical treatment of the cavus foot depends on a fundamental understanding of the underlying multiplanar deformity, inherent muscle balance, and the rigidity of the hindfoot. The location of the deformity is described and understood according to its multiple apices. These deformities are addressed with osteotomies or arthrodesis directed at the apices of deformity. Simultaneously, correction of muscular imbalances with appropriate tendon transfers must also be performed to prevent recurrent deformity. With these principles in mind, the surgical correction of the cavus foot becomes simplified and algorithmically driven.

Does native glenoid anatomy predispose to shoulder instability? An MRI analysis.

BACKGROUND: It is unclear if native glenohumeral anatomic features predispose young patients to instability and if such anatomic risk factors differ between males and females. The purpose of this study was to compare glenoid and humeral head dimensions between patients with a documented instability event without bone loss to matched controls and to evaluate for sex-based differences across measurements. The authors hypothesized that a smaller glenoid width and glenoid surface area would be significant risk factors for instability, whereas humeral head width would not. METHODS: A prospectively maintained database was queried for patients aged <21 years who underwent magnetic resonance imaging (MRI) for shoulder instability. Patients with prior shoulder surgery, bony Bankart, or glenoid or humeral bone loss were excluded. Patients were matched by sex and age to control patients who had no history of shoulder instability. Two blinded independent raters measured glenoid height, glenoid width, and humeral head width on sagittal MRI. Glenoid surface area, glenoid index (ratio of glenoid height to width), and glenohumeral mismatch ratio (ratio of humeral head width to glenoid width) were calculated. RESULTS: A total of 107 instability patients and 107 controls were included (150 males and 64 females). Among the entire cohort, there were no differences in glenoid height, glenoid width, glenoid surface area, humeral head width, or glenoid index between patients with instability and controls. Overall, those with instability had a greater glenohumeral mismatch ratio (P = .029) compared with controls. When stratified by sex, female controls and instability patients showed no differences in any of the glenoid or humerus dimensions. However, males with instability had a smaller glenoid width by 3.5% (P = .017), smaller glenoid surface area by 5.2% (P = .015), and a greater glenohumeral mismatch ratio (P = .027) compared with controls. CONCLUSION: Compared with controls, males with instability were found to have smaller glenoid width and surface area, and a glenoid width that was proportionally smaller relative to humeral width. In contrast, bony glenohumeral morphology did not appear to be a significant risk factor for instability among females. These sex-based differences suggest that anatomic factors may influence risk of instability for male and female patients differently.

Diagnostic Performance of Artificial Intelligence for Detection of Anterior Cruciate Ligament and Meniscus Tears: A Systematic Review.

PURPOSE: To (1) determine the diagnostic efficacy of artificial intelligence (AI) methods for detecting anterior cruciate ligament (ACL) and meniscus tears and to (2) compare the efficacy to human clinical experts. METHODS: PubMed, OVID/Medline, and Cochrane libraries were queried in November 2019 for research articles pertaining to AI use for detection of ACL and meniscus tears. Information regarding AI model, prediction accuracy/area under the curve (AUC), sample sizes of testing/training sets, and imaging modalities were recorded. RESULTS: A total of 11 AI studies were identified: 5 investigated ACL tears, 5 investigated meniscal tears, and 1 investigated both. The AUC of AI models for detecting ACL tears ranged from 0.895 to 0.980, and the prediction accuracy ranged from 86.7% to 100%. Of these studies, 3 compared AI models to clinical experts. Two found no significant differences in diagnostic capability, whereas one found that radiologists had a significantly greater sensitivity for detecting ACL tears (P = .002) and statistically similar specificity and accuracy. Of the 5 studies investigating the meniscus, the AUC for AI models ranged from 0.847 to 0.910 and prediction accuracy ranged from 75.0% to 90.0%. Of these studies, 2 compared AI models with clinical experts. One found no significant differences in diagnostic accuracy, whereas one found that the AI model had a significantly lower specificity (P = .003) and accuracy (P = .015) than radiologists. Two studies reported that the addition of AI models significantly increased the diagnostic performance of clinicians compared to their efforts without these models. CONCLUSIONS: AI prediction capabilities were excellent and may enhance the diagnosis of ACL and meniscal pathology; however, AI did not outperform clinical experts. CLINICAL RELEVANCE: AI models promise to improve diagnosing certain pathologies as well as or better than human experts, are excellent for detecting ACL and meniscus tears, and may enhance the diagnostic capabilities of human experts; however, when compared with these experts, they may not offer any significant advantage.

Regenerative Potential of Mesenchymal Stem Cells for the Treatment of Knee Osteoarthritis and Chondral Defects: A Systematic Review and Meta-analysis.

PURPOSE: To perform a systematic review and meta-analysis evaluating the effects of mesenchymal stem cells (MSCs) on cartilage regeneration and patient-reported pain and function. METHODS: A systematic review was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using a PRISMA checklist. The Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (2008-2019), EMBASE (2008-2019), and MEDLINE (2008-2019) were queried in July 2019 for literature reporting use of stem cells to treat knee osteoarthritis or chondral defects. Data describing administered treatment, subject population, injection type, duration of follow-up, pain and functional outcomes, and radiographic and magnetic resonance imaging findings were extracted. Risk of bias was assessed using the Downs and Black scale. Meta-analyses adjusted for random effects were performed, calculating pooled effect sizes in terms of patient-reported pain and function, cartilage quality, and cartilage volume. RESULTS: Twenty-five studies with 439 subjects were identified. There was no significant difference in pain improvement between MSC treatment and controls (pooled standardized mean difference [SMD] = 0.23, P = .30). However, MSC treatment was significantly favored for functional improvement (SMD = 0.66, P < .001). There was improvement in cartilage volume after MSC treatment (SMD = 0.84, P < .001). Regarding cartilage quality, meta-analysis resulted in a small, nonsignificant effect size of 0.37 (95%, -0.03 to 0.77, P = .07). There was risk for potential bias among included studies, with 17 (68%) receiving either a grade of "poor" or "fair." CONCLUSIONS: The pooled SMD from meta-analyses showed statistically significant effects of MSC on self-reported physical function but not self-reported pain. MSCs provided functional benefit only in patients who underwent concomitant surgery. However, this must be interpreted with caution, as there was substantial variability in MSC composition and mode of delivery. MSC treatment provided significant improvement in cartilage volume but not cartilage quality. Preliminary data regarding therapeutic properties of MSC treatment suggest significant heterogeneity in the current literature, and risk of bias is not negligible. LEVEL OF EVIDENCE: II, Systematic Review and Meta-analysis.

Patient Factors Associated With Clinical Failure Following Arthroscopic Superior Capsular Reconstruction.

PURPOSE: To identify demographic, clinical, and radiographic factors associated with failure after superior capsular reconstruction (SCR). METHODS: Prospectively collected data were analyzed from patients who underwent SCR using a decellularized dermal allograft for an irreparable rotator cuff tear. Demographic characteristics, radiographic findings, concomitant procedures, and patient-reported outcomes (PROs) were recorded. Failure was defined by ≥1 of the following criteria: (1) conversion to reverse total shoulder arthroplasty (RTSA), (2) a decrease in 1-year postoperative shoulder-specific PROs compared with preoperative scores, or (3) patient reports at final follow-up that the shoulder was in a worse condition than before surgery. Preoperative variables were compared between patients meeting the criteria for clinical failure and those who did not. RESULTS: Fifty-four patients (mean age 56.3 ± 5.8 years, range 45 to 70) who underwent SCR, with minimum 1-year follow-up, were included in the analysis. Mean follow-up after surgery was 24 months (range 12 to 53). Eleven patients (20.4%) met criteria for clinical failure. Of the 11, 8 reported decreased American Shoulder and Elbow Surgeons (ASES) or Constant scores or indicated that the operative shoulder was in a worse condition than before surgery. Three patients underwent RTSA in the 6 to 12 months after SCR. Female sex and the presence of a subscapularis tear were associated with failure (P = .023 and P = .029, respectively). A trend toward greater body mass index (BMI), lower preoperative forward flexion, and lower preoperative acromiohumeral distance (AHD) was found in patients with clinical failure (P = .075, P = .088, and P = .081, respectively). No other variable included in the analysis was significantly associated with failure. CONCLUSION: The proportions of female patients and those with subscapularis tear were greater among patients with clinical failure after SCR. Greater BMI, lower preoperative forward flexion, and lower preoperative AHD trended toward association with clinical failure of SCR. LEVEL OF EVIDENCE: 4, case series.

Editorial Commentary: Shedding Light on the Posterolateral Corner of the Knee: Can We Do it With the Scope? Is There a Real Benefit?

Historically described as the "dark side of the knee," the posterolateral corner of the knee has been a significant focus of anatomic, biomechanical, and clinical outcomes research due to poor treatment outcomes for these injuries before improvements over the past 2 decades. These research efforts have resulted in significant improvements in the understanding, diagnosis, and surgical treatment of these injuries. Perhaps most importantly, improved understanding of the anatomy and biomechanics has led to the development of anatomic-based reconstructions, which have been subsequently validated with both biomechanical and clinical outcomes. Due to the complex anatomy and proximity of neurovascular structures, reconstructions have historically used large "hockey stick" incisions to provide adequate visualization to identify the anatomic insertions of the static stabilizers and ensure adequate protection of neurovascular structures. These anatomic-based techniques have significantly improved the clinical and objective outcomes of the surgical treatment of posterolateral knee injuries. However, as techniques have evolved and the clinical outcomes have improved, clinicians have attempted to develop and employ less-invasive and arthroscopically assisted techniques. Specifically, given the steep learning curve, paucity of clinical outcomes, increased operative time, and the limited view of the anatomy, which may increase the risk of nonanatomic tunnel placement, and injuries to surrounding structures, we cannot support an arthroscopic approach at this time.

Posterior Cruciate Ligament.

Improved understanding of the anatomy and biomechanics of the posterior cruciate ligament (PCL) has led to the evolution and improvement of anatomic-based reconstructions. The PCL is composed of the larger anterolateral bundle (ALB) and the smaller posteromedial bundle (PMB). On the femoral side, the ALB spans from the trochlear point to the medial arch point on the roof of the notch, while the PMB occupies the medial wall from the medial arch point to the most posterior aspect of the articular cartilage. Because of these broad and distinct attachments, the bundles have a load-sharing, synergistic and codominant relationship. Both restrict posterior translation; however, the ALB has a proportionally larger role in restricting translation throughout flexion, whereas the PMB has a role comparable to that of the ALB in full extension. In addition, the PMB resists internal rotational at greater flexion angles (> 90°). Consequently, it is difficult to restore native kinematics with a single graft. Biomechanical analysis of single- versus double-bundle PCL reconstructions (SB PCLR vs DB PCLR) demonstrates improved restoration of native kinematics with a DB PCLR, including resistance to posterior translation throughout flexion (15°-120°) and internal rotation in deeper flexion (90°-120°). Similarly, clinical research demonstrates excellent outcomes following DB PCLR, including functional outcomes comparable to those of anterior cruciate ligament reconstructions, with no significant differences between isolated and multiligament PCL injuries. Compared to SB PCLR, systematic review has demonstrated the superiority of DB PCLR based on objective postoperative stress radiography and International Knee Documentation Committee scores in randomized trials. In addition to reconstruction techniques, recent research has identified other factors that impact kinematics and PCL forces, including decreased tibial slope, which leads to increased graft stresses, and incidence of native PCL injuries. As the understanding of these other contributing factors evolves, so will surgical and treatment algorithms that will further improve patients' outcomes.

No Differences in Hip Joint Space Measurements Between Weightbearing or Supine Anteroposterior Pelvic Radiographs.

PURPOSE: To to assess whether there are any significant differences in hip joint space width (JSW) between weight-bearing versus supine pelvic radiographs. METHODS: Standing and supine anteroposterior pelvic radiographs of 86 patients (146 hips) were included. Sample size was sufficiently powered to assess for equivalence between standing and supine films for JSW measurements made at the medial, lateral, and central aspects of the sourcil line. Measurements were made by 2 independent reviewers blinded to patient positioning. Each reviewer repeated a subset of the measurements to assess intra-rater reproducibility. Mean differences in joint space measurements between standing and supine radiographs were reported for each point of the sourcil. Intraclass correlation coefficients (ICCs) for inter and intra-rater reliability were also calculated. RESULTS: There were no significant differences between JSW measurements made on standing and supine pelvic radiographs (P = .468). Furthermore, equivalence testing demonstrated statistical equivalence between standing and supine JSW measurements made based on an equivalence threshold of ±0.5 mm. Inter-rater reliability demonstrated good agreement with an overall ICC of 0.775 (95% confidence interval [CI] 0.734-0.809). Intra-rater reliability also demonstrated good agreement with ICCs of 0.84 (95% CI 0.758-0.889) and 0.798 (95% CI 0.721-0.851) for the 2 reviewers, respectively. CONCLUSIONS: JSW measurements on standing and supine pelvic radiographs were not significantly different, and their inter-rater agreement and intra-rater reproducibility demonstrated good reliability and repeatability. Therefore, either may be used to assess JSW, including measurements that may impact treatment decisions for hip arthroscopy. LEVEL OF EVIDENCE: Level III; retrospective comparative study.

Outcomes and Survivorship After Arthroscopic Treatment of Glenohumeral Arthritis: A Systematic Review.

PURPOSE: To perform a systematic review of the literature describing outcomes, surgical procedures, and rates of conversion to arthroplasty after arthroscopic debridement of symptomatic primary glenohumeral osteoarthritis. METHODS: The Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, PubMed, Embase, and Ovid MEDLINE were queried. Articles without sufficiently detailed descriptions of the debridement procedure, those primarily describing cartilage resurfacing procedures, or those that did not report any postoperative outcomes were excluded. Study design, patient demographic characteristics, operative details, imaging findings, patient-reported outcomes, and rates of conversion to arthroplasty were compiled and reported. Assessment of bias was performed using the Methodological Index for Non-randomized Studies (MINORS) criteria. RESULTS: A total of 371 patients (382 shoulders) in 8 studies were included. Patient sample sizes ranged from 8 patients (9 shoulders) to 98 patients (107 shoulders), and the samples were predominantly comprised of male patients (range, 57.1%-100%). The mean age and follow-up period ranged from 38 to 59 years and from 13.7 to 46.8 months, respectively. In studies reporting both preoperative and postoperative outcomes, improvements were found in American Shoulder and Elbow Surgeons scores (range, 8.6-22) and visual analog scale scores for pain (range, 0.4-3.8). There was significant heterogeneity (I2 = 75%) in the rates of conversion to shoulder arthroplasty, which ranged from 4% to 42.4%, with the mean time to conversion ranging from 9 to 56 months. Study heterogeneity improved with subgroup analyses based on minimum duration of follow-up (>2 years) and preoperative radiographic inclusion criteria. CONCLUSIONS: Arthroscopic treatment of glenohumeral osteoarthritis provides improvements in ROM and patient-reported outcomes with minimal complications. Despite variability in procedures and rates of subsequent conversion to arthroplasty, arthroscopic treatment appears to provide symptom relief and functional improvements in carefully selected patients. However, the longevity of improvement remains unclear, with studies including a longer duration of follow-up showing potential regression of symptom relief and increased rates of conversion to arthroplasty. LEVEL OF EVIDENCE: Level IV, systematic review of Level III and IV studies.

Do Corticosteroid Injections Before or After Primary Rotator Cuff Repair Influence the Incidence of Adverse Events? A Subjective Synthesis.

PURPOSE: To determine the influence of corticosteroid injections (CSIs) before or after primary rotator cuff repair (RCR) on the risk of (1) revision RCR, (2) retears, and (3) infections. METHODS: The Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, PubMed, Embase, and MEDLINE databases were queried in accordance with the 2009 Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Data pertaining to the use of CSIs before or after primary RCR and adverse events were extracted. A subjective synthesis of these outcomes and bias was performed. RESULTS: A total of 10 studies including 240,976 patients were identified; 20.0% received a perioperative CSI. Of the 48,235 patients who received a CSI, 66.2% did so preoperatively whereas 33.8% did so postoperatively. A total of 78 patients received both preoperative and postoperative CSIs. Three studies examined the influence of preoperative CSIs on revision RCR; the incidence ranged from 3.8% to 10.5% with preoperative CSIs and from 3.2% to 3.4% for controls. Two of these studies analyzed outcomes of patients from the same databases over the same period. Five studies examined the influence of postoperative CSI use on retears; the incidence ranged from 5.7% to 19.0% in patients who received postoperative CSIs and from 10.0% to 18.4% for controls. Three studies examined the influence of CSI use on infection; 2 studies examined the risk of infection after postoperative CSI use, which ranged from 0.0% to 6.7% with CSIs and from 0.0% to 0.5% for controls. CONCLUSIONS: The use of preoperative CSIs could be associated with an increased risk of revision RCR. There were no conclusive data to suggest an increased risk of retear or infection with CSI use based on a subjective synthesis of ranges. There is currently poor-quality literature surrounding this topic. Given that the current literature is limited and heterogeneous, no definitive recommendations can be made on perioperative CSI use for RCR. LEVEL OF EVIDENCE: Level III, systematic review of Level I and III studies.

Influence of preoperative opioid use on postoperative outcomes and opioid use after arthroscopic rotator cuff repair.

BACKGROUND: Recent orthopedic research has questioned the effect of opioid use on surgical outcomes. This study investigated this in the context of arthroscopic rotator cuff repair. We hypothesized that preoperative opioid use would be associated with inferior outcomes and greater postoperative opioid requirements. METHODS: A database query identified adult patients with full-thickness or partial-thickness supraspinatus tears surgically treated between 2011 and 2015. Preoperative and postoperative outcomes scores (active range of motion [AROM], American Shoulder and Elbow Surgeons [ASES], Constant scores, Simple Shoulder Test [SST], and visual analog scale [VAS] for pain) and postoperative opioid use were retrospectively recorded. Patients with less than 2 years of follow-up data at the time of the retrospective review were contacted for prospective ASES, SST, and VAS data collection. RESULTS: A total of 200 patients, 44 of whom received opioids preoperatively, were identified for inclusion. Patients prescribed preoperative opioids had consistently inferior preoperative and postoperative outcomes scores; however, the magnitudes of improvement were not significantly different between groups. Postoperatively, patients in the preoperative opioid group received 1.91 (95% confidence interval, 1.31-2.78) times more opioids over a postoperative course of treatment that was 2.73 (95% confidence interval, 1.62-4.59) times longer. In addition to having a greater proportion of women, this group also had significantly higher rates of certain comorbidities, including back pain, depression, degenerative joint disease, and chronic pain conditions. CONCLUSIONS: All patients demonstrated significant improvements in outcomes scores after surgical repair that were not significantly different between groups. However, patients taking opioids preoperatively did not ultimately reach the same level of functionality and had substantially greater opioid requirements postoperatively.

High-load preconditioning of human soft tissue hamstring grafts: An in vitro biomechanical analysis.

PURPOSE: In order to minimize viscoelastic elongation of ACL reconstruction grafts, preconditioning protocols have been employed in clinical practice prior to final graft fixation. The purpose of this study was to evaluate two separate high-load static preconditioning protocols of double-looped semitendinosus-gracilis grafts and compare these results to both a current clinical protocol and a control group with no preconditioning protocol applied. It was hypothesized that a high-load, static preconditioning protocol would minimize graft elongation during a simulated progressive early rehabilitation compared to both the "89 N" clinical protocol and control groups. METHODS: Grafts were randomly allocated into four preconditioning study groups: (1) control (no preconditioning), (2) clinical protocol (89 N for 15 min), (3) high-load, short duration (600 N for 20 s), and (4) high-load, long duration (600 N for 15 min). After preconditioning, grafts were cyclically loaded between 10 and 400 N at 0.5 Hz for 450 cycles to simulate early postoperative rehabilitation. Graft displacement (elongation) was recorded during both preconditioning and cyclic loading. RESULTS: Increased preconditioning load magnitude and duration significantly reduced graft elongation during cyclic loading (p < 0.05) which corresponded to an inverse relationship with increased elongation during preconditioning. The "600 N for 15 min" protocol resulted in significantly less elongation during simulated early rehabilitation than both the control group and the "89 N for 15 min" protocol (p < 0.001, p < 0.05). CONCLUSIONS: Graft elongation during simulated early rehabilitation was significantly reduced by a high-load preconditioning protocol applied for an extended period of time compared to a current common clinical protocol and grafts that were not preconditioned. In addition, the amount of elongation during simulated early rehabilitation was similar between grafts preconditioned using the current clinical practice protocol and the high-load/short-duration protocol, implying that the latter could potentially induce the same viscoelastic changes in soft tissue grafts as the current clinical practice. The "600 N for 20 s" preconditioning protocol may provide similar postoperative results as the clinical protocol, "89 N for 15 min", and also reduce or maintain operative time. A high-load preconditioning protocol that reduces graft elongation may benefit patients undergoing ACL reconstruction, especially for cases of failed primary reconstruction, genu recurvatum, and increased tibial slope, where maintaining graft length is imperative to restore knee stability.

A physeal-sparing fibular collateral ligament and proximal tibiofibular joint reconstruction in a skeletally immature athlete.

The purpose of this report was to describe the surgical technique for and outcomes after a modified physeal-sparing posterolateral corner reconstruction in a 12-year-old skeletally immature male with a mid-substance fibular collateral ligament tear, a proximal posterior tibiofibular ligament tear, and an anterior cruciate ligament avulsion fracture of the medial tibial eminence. A modified physeal-sparing posterolateral corner reconstruction was used to provide a near-anatomic reconstruction of the fibular collateral ligament and proximal posterior tibiofibular ligament. An anterior cruciate ligament repair was also performed. Varus stress radiographs obtained at 6 months postoperatively demonstrated resolution of lateral knee stability. Physical examination results demonstrated stability to anterior tibial translation and a stable proximal tibiofibular joint. Computed tomography showed that the surgical technique successfully avoided breeching the patient's physes.

Radiographic identification of the primary structures of the ankle syndesmosis.

PURPOSE: The purpose of this study was to quantitatively describe the locations of the syndesmotic ligaments and the tibiofibular articulating cartilage surfaces on standard radiographic views using reproducible radiographic landmarks and reference axes. METHODS: Twelve non-paired ankles were dissected to identify the anterior-inferior tibiofibular ligament (AITFL), posterior-inferior tibiofibular ligament (PITFL), interosseous tibiofibular ligament (ITFL), and the cartilage surfaces of the syndesmosis. Structures were marked with 2-mm radiopaque spheres prior to obtaining lateral and mortise radiographs. Measurements were performed by two independent raters to assess intra- and interobserver reliability via intraclass correlation coefficients (ICCs). RESULTS: Measurements demonstrated excellent agreement between observers and across trials (all ICCs ≥ 0.960). On the lateral view, the AITFL tibial origin was 9.6 ± 1.5 mm superior and posterior to the anterior tibial plafond. Its fibular insertion was 4.4 ± 1.7 mm superior and posterior to the anterior fibular tubercle. The centre of the tibial cartilage facet of the tibiofibular contact zone was 8.4 ± 2.1 mm posterior and superior to the anterior plafond. The proximal and distal aspects of the ITFL tibial attachment were 45.9 ± 7.9 and 12.4 ± 3.4 mm proximal to the central plafond, respectively. The superficial and deep PITFL coursed anterior and distally from the posterior tibia to fibula. On the mortise view, the AITFL tibial attachment centre was 5.6 ± 2.4 mm lateral and superior to the lateral extent of the plafond (4.3 mm lateral, 3.3 mm superior), and its fibular insertion was 21.2 ± 2.1 mm superior and medial to the inferior tip of the lateral malleolus. CONCLUSIONS: Quantitative radiographic guidelines describing the locations of the primary syndesmotic structures demonstrated excellent reliability and reproducibility. Defined guidelines provide additional clinically relevant information regarding the radiographic anatomy of the syndesmosis and may assist with preoperative planning, augment intraoperative navigation, and provide additional means for objective postoperative assessment.

High-load preconditioning of soft tissue grafts: an in vitro biomechanical bovine tendon model.

PURPOSE: No consensus exists regarding the optimal preconditioning protocol that will minimize postoperative elongation while creating a graft that is biomechanically equivalent to the native anterior cruciate ligament (ACL). It was hypothesized that a preconditioning protocol of specific mode and magnitude would create a graft with equivalent stiffness to the native ACL. METHODS: Thirty-six bovine extensor tendon grafts were randomly allocated among six preconditioning groups (n = 6 per group) including three cyclic (10 cycles at 0.5 Hz between 10-80, 100-300, and 300-600 N) and three static loading protocols (20 s at 80, 300, and 600 N). Grafts were then cyclically loaded between 50 and 250 N at 0.5 Hz for 500 cycles to simulate an early rehabilitation protocol. RESULTS: Cyclic 300-600 N and static 600 N loading protocols both demonstrated significantly less elongation during simulated rehabilitation when compared to lower, current clinical standard preconditioning levels of 10-80 N (-62% Δ) and 80 N (-69% Δ). The same high-load preconditioning protocols demonstrated statistical equivalence in stiffness when compared to the previously reported stiffness of the native ACL. CONCLUSIONS: In this experimental model, increased force applied to soft tissue grafts during preconditioning significantly decreased the subsequent elongation experienced during simulated early rehabilitation. A static load of 600 N removed the most graft elongation during preconditioning, had the least amount of cyclic displacement during simulated early rehabilitation, and was statistically equivalent to the native ACL stiffness. Implementation of high-load preconditioning of soft tissue grafts may help improve outcomes following ACL reconstruction by reducing residual knee laxity resulting from postoperative graft elongation and the intrinsic viscoelastic properties of the graft tissue while imparting biomechanical characteristics (e.g. stiffness) equivalent to the native ACL.

Lack of consensus regarding pretensioning and preconditioning protocols for soft tissue graft reconstruction of the anterior cruciate ligament.

PURPOSE: Pretensioning and preconditioning of soft tissue grafts are often performed to obviate graft stress relaxation and elongation due to viscoelastic graft properties following anterior cruciate ligament (ACL) reconstruction. It was hypothesized that a consensus could be identified in the current literature regarding the biomechanical effects and clinical benefits of an optimal protocol. METHODS: A systematic electronic literature search was performed by two independent reviewers to identify relevant publications. Only studies describing and/or comparing pretensioning or preconditioning protocols of soft tissue grafts or equivalent animal research models were eligible for inclusion. Study design, graft type, and protocol, including method, magnitude, mode (cyclic and/or static loading), and duration of load application, were compared. Research results and clinical conclusions were also evaluated for each study. RESULTS: Five studies, including four in vitro biomechanical investigations and one histological analysis of patient tissue, met the predefined criteria for inclusion. Studies described numerous pretensioning and/or preconditioning protocols with varying force, time, and application modalities for multiple soft tissue graft types and animal models. The majority of studies (80 %) utilized at least one pretensioning or preconditioning protocol between 80 and 89 N, while only one study investigated substantially higher loads (500 N). CONCLUSIONS: Despite common trends demonstrating the effects of pretensioning and preconditioning, no clear consensus regarding an optimal protocol, magnitude, or modality could be identified within the currently available relevant literature. Further multidisciplinary research is required before an optimal or consensus protocol can be established for soft tissue ACL reconstruction. Regardless, the current biomechanical literature demonstrates the potential clinically beneficial effects of pretensioning and preconditioning, including reduced graft elongation and greater preservation of graft tension and stiffness following fixation. LEVEL OF EVIDENCE: Systematic review, Level II.

Magnetic resonance imaging characterization of individual ankle syndesmosis structures in asymptomatic and surgically treated cohorts.

PURPOSE: Historically, syndesmosis injuries have been underdiagnosed. The purpose of this study was to characterize the 3.0-T MRI presentations of the distal tibiofibular syndesmosis and its individual structures in both asymptomatic and injured cohorts. METHODS: Ten age-matched asymptomatic volunteers were imaged to characterize the asymptomatic syndesmotic anatomy. A series of 21 consecutive patients with a pre-operative 3.0-T ankle MRI and subsequent arthroscopic evaluation for suspected syndesmotic injury were reviewed and analysed. Prospectively collected pre-operative MRI findings were correlated with arthroscopy to assess diagnostic accuracy [sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV)]. RESULTS: Pathology diagnosed on pre-operative MRI correlated strongly with arthroscopic findings. Syndesmotic ligament disruption was prospectively diagnosed on MRI with excellent sensitivity, specificity, PPV, NPV, and accuracy: anterior inferior tibiofibular ligament (87.5, 100, 100, 71.4, 90.5 %); posterior inferior tibiofibular ligament (N/A, 95.2, 0.0, 100, 95.2 %); and interosseous tibiofibular ligament (66.7, 86.7, 66.7, 86.7, 81.0 %). CONCLUSIONS: Pre-operative 3.0-T MRI demonstrated excellent accuracy in the diagnosis of syndesmotic ligament tears and allowed for the visualization of relevant individual syndesmosis structures. Using a standard clinical ankle MRI protocol at 3.0-T, associated ligament injuries could be readily identified. Clinical implementation of optimal high-field MRI sequences in a standard clinical ankle MRI exam can aid in the diagnosis of syndesmotic injuries, augment pre-operative planning, and facilitate anatomic repair by providing additional details regarding the integrity of individual syndesmotic structures not discernible through physical examination and radiographic assessments. LEVEL OF EVIDENCE: II.

Stress radiography for the diagnosis of knee ligament injuries: a systematic review.

BACKGROUND: Stress radiography is a widely used diagnostic tool to assess injury to the anterior and posterior cruciate ligaments and the medial and lateral structures of the knee. However, to date, numerous techniques have been reported in the literature with no clear consensus as to which methodology is best for assessing ligament stability. QUESTIONS/PURPOSES: The purpose of this review was to identify which stress radiographic techniques have support in the literature for the diagnosis of acute or chronic knee ligament injuries, to define which technique is most accurate and reliable for diagnosing knee ligament injuries, and to compare the use of stress radiography with other diagnostic tests. METHODS: Two independent reviewers performed a systematic review of PubMed (MEDLINE), the EMBASE library, and the Cochrane Controlled Trials Register for English language studies published from January 1970 to August 2013 on the diagnosis of knee ligament injuries using stress radiography. Information describing the ligament(s) investigated, stress radiographic technique, magnitude of force, measures of accuracy and reliability, and comparative diagnostic tests were extracted. Risk of bias was assessed using the QUADAS-2 tool. RESULTS: A total of 16 stress techniques were described for stress radiography of the knee. The diagnostic accuracy of stress radiography including the sensitivity, specificity, and positive and negative predictive values varied considerably depending on the technique and choice of displacement or gapping threshold. Excellent reliability was reported for the diagnosis of anterior cruciate ligament, posterior cruciate ligament, varus, and valgus knee injuries. Inconsistencies were found across studies regarding the efficacy of stress radiography compared with other diagnostic modalities. CONCLUSIONS: Based on the multitude of stress techniques reported, varying levels of diagnostic accuracy, and inconsistencies regarding comparative efficacy of stress radiography to other diagnostic modalities, we are not able to make specific recommendations with regard to the best stress radiography technique for the diagnosis of knee ligament injuries. Additional comparative studies using consistent methodology and appropriate blinding are necessary to further define differences in accuracy and reliability both among stress radiography techniques and between stress radiography and other diagnostic tests. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Indirect Head of the Rectus Femoris Tendon as a Graft for Segmental Hip Labral Reconstruction: An Anatomic, Radiographical, and Biomechanical Study in Comparison With Iliotibial Labral Reconstruction.

BACKGROUND: The indirect head of the rectus femoris (IHRF) tendon has been used as an autograft for segmental labral reconstruction. However, the biomechanical properties and anatomic characteristics of the IHRF, as they relate to surgical applications, have yet to be investigated. PURPOSE: To (1) quantitatively and qualitatively describe the anatomy of IHRF and its relationship with surrounding arthroscopically relevant landmarks; (2) detail radiographic findings pertinent to IHRF; (3) biomechanically assess segmental labral reconstruction with IHRF, including restoration of the suction seal and contact pressures in comparison with iliotibial band (ITB) reconstruction; and (4) assess potential donor-site morbidity caused by graft harvesting. STUDY DESIGN: Descriptive laboratory study. METHODS: A cadaveric study was performed using 8 fresh-frozen human cadaveric full pelvises and 7 hemipelvises. Three-dimensional anatomic measurements were collected using a 3-dimensional coordinate digitizer. Radiographic analysis was accomplished by securing radiopaque markers of different sizes to the evaluated anatomic structures of the assigned hip.Suction seal and contact pressure testing were performed over 3 trials on 6 pelvises under 4 different testing conditions for each specimen: intact, labral tear, segmental labral reconstruction with ITB, and segmental labral reconstruction with IHRF. After IHRF tendon harvest, each full pelvis had both the intact and contralateral hip tested under tension along its anatomic direction to assess potential site morbidity, such as tendon failure or bony avulsion. RESULTS: The centroid and posterior apex of the indirect rectus femoris attachment are respectively located 10.3 ± 2.6 mm and 21.0 ± 6.5 mm posteriorly, 2.5 ± 7.8 mm and 0.7 ± 8.0 mm superiorly, and 5.0 ± 2.8 mm and 22.2 ± 4.4 mm laterally to the 12:30 labral position. Radiographically, the mean distance of the IHRF to the following landmarks was determined as follows: anterior inferior iliac spine (8.8 ± 2.5 mm), direct head of the rectus femoris (8.0 ± 3.9 mm), 12-o'clock labral position (14.1 ± 2.8 mm), and 3-o'clock labral position (36.5 ± 4.4 mm). During suction seal testing, both the ITB and the IHRF reconstruction groups had significantly lower peak loads and lower energy to peak loads compared with both intact and tear groups (P = .01 to .02 for all comparisons). There were no significant differences between the reconstruction groups for peak loads, energy, and displacement at peak load. In 60° of flexion, there were no differences in normalized contact pressure and contact area between ITB or IHRF reconstruction groups (P > .99). There were no significant differences between intact and harvested specimen groups in donor-site morbidity testing. CONCLUSION: The IHRF tendon is within close anatomic proximity to arthroscopic acetabular landmarks. In the cadaveric model, harvesting of the IHRF tendon as an autograft does not lead to significant donor-site morbidity in the remaining tendon. Segmental labral reconstruction performed with the IHRF tendon exhibits similar biomechanical outcomes compared with that performed with ITB. CLINICAL RELEVANCE: This study demonstrates the viability of segmental labral reconstruction with an IHRF tendon and provides a detailed anatomic description of the tendon in the context of an arthroscopic labral reconstruction. Clinicians can use this information during the selection of a graft and as a guide during an arthroscopic graft harvest.

The Large Focal Isolated Chondral Lesion.

Focal chondral defects (FCDs) of the knee can be a debilitating condition that can clinically translate into pain and dysfunction in young patients with high activity demands. Both the understanding of the etiology of FCDs and the surgical management of these chondral defects has exponentially grown in recent years. This is reflected by the number of surgical procedures performed for FCDs, which is now approximately 200,000 annually. This fact is also apparent in the wide variety of available surgical approaches to FCDs. Although simple arthroscopic debridement or microfracture are usually the first line of treatment for smaller lesions, chondral lesions that involve a larger area or depth require restorative procedures such as osteochondral allograft transplantation or other cell-based techniques. Given the prevalence of FCDs and the increased attention on treating these lesions, a comprehensive understanding of management from diagnosis to rehabilitation is imperative for the treating surgeon. This narrative review aims to describe current concepts in the treatment of large FCDs through providing an algorithmic approach to selecting interventions to address these lesions as well as the reported outcomes in the literature.