Enthesis repair - State of play.

The fibrocartilaginous enthesis is a highly specialised tissue interface that ensures a smooth mechanical transfer between tendon or ligament and bone through a fibrocartilage area. This tissue is prone to injury and often does not heal, even after surgical intervention. Enthesis augmentation approaches are challenging due to the complexity of the tissue that is characterised by the coexistence of a range of cellular and extracellular components, architectural features and mechanical properties within only hundreds of micrometres. Herein, we discuss enthesis repair and regeneration strategies, with particular focus on elegant interfacial and functionalised scaffold-based designs.

Fibrocartilaginous Tissue: Why Does It Fail to Heal?

Tendons and ligaments are critical components in the function of the musculoskeletal system, as they provide stability and guide motion for the biomechanical transmission of forces into bone. Several common injuries in the foot and ankle require the repair of ruptured or attenuated tendon or ligament to its osseous insertion. Understanding the structure and function of injured ligaments and tendons is complicated by the variability and unpredictable nature of their healing. The healing process at the tendon/ligament to bone interface is challenging and often frustrating to foot and ankle surgeons, as they have a high failure rate necessitating the need for revision.

Role of Scx+/Sox9+ cells as potential progenitor cells for postnatal supraspinatus enthesis formation and healing after injury in mice.

A multipotent cell population co-expressing a basic-helix-loop-helix transcription factor scleraxis (Scx) and SRY-box 9 (Sox9) has been shown to contribute to the establishment of entheses (tendon attachment sites) during mouse embryonic development. The present study aimed to investigate the involvement of Scx+/Sox9+ cells in the postnatal formation of fibrocartilaginous entheses and in the healing process after injury, using ScxGFP transgenic mice. We demonstrate that Scx+/Sox9+ cells are localized in layers at the insertion site during the postnatal formation of fibrocartilaginous entheses of supraspinatus tendon until postnatal 3 weeks. Further, these cells were rarely seen at postnatal 6 weeks, when mature fibrocartilaginous entheses were formed. Furthermore, we investigated the involvement of Scx+/Sox9+ cells in the healing process after supraspinatus tendon enthesis injury, comparing the responses of 20- and 3-week-old mice. In the healing process of 20-week-old mice with disorganized fibrovascular tissue in response to injury, a small number of Scx+/Sox9+ cells transiently appeared from 1 week after injury, but they were rarely seen at 4 weeks after injury. Meanwhile, in 3-week-old mice, a thin layer of fibrocartilaginous tissue with calcification was formed at healing enthesis at 4 weeks after injury. From 1 to 2 weeks after injury, more Scx+/Sox9+ cells, widely distributed at the injured site, were seen compared with the 20-week-old mice. At 4 weeks after injury, these cells were located near the surface of the recreated fibrocartilaginous layer. This spatiotemporal localization pattern of Scx+/Sox9+ cells at the injured enthesis in our 3-week-old mouse model was similar to that in postnatal fibrocartilaginous enthesis formation. These findings indicate that Scx+/Sox9+ cells may have a role as entheseal progenitor-like cells during postnatal maturation of fibrocartilaginous entheses and healing after injury in a manner similar to that seen in embryonic development.

Problems of Eponymous Proportions: The History Behind Recognizing Forearm Instability Issues.

Three predictable patterns of forearm fracture-dislocation-Essex-Lopresti, Monteggia, and Galeazzi-can occur and are eponymously labeled for the investigators who appreciated their unique characteristics and offered a framework by which to understand them. Recognition of these injuries and subsequent investigation and increased understanding of these lesions have resulted in improved understanding about forearm anatomy and stability. Management of the component of instability differs based on the type of fracture-dislocation, the timing of intervention, and surgeon preference. Despite advances in understanding and treating these injuries, nuances of these lesions may remain challenging to modern-day surgeons.

The Diagnostic Value of Ultrasound in Anterosuperior Acetabular Labral Tear.

PURPOSE: To investigate diagnostic value of ultrasound in acetabular labral tears compared with magnetic resonance (MR) imaging, using arthroscopic surgery as the gold standard in a relatively large sample size. METHODS: We retrospectively evaluated patients who attended the sports medicine clinic of our department and underwent arthroscopic surgery for the diagnosis of an anterosuperior acetabular labral tear between June 2014 and April 2018. All the patients received hip joint ultrasound examination and MR imaging evaluation before arthroscopic surgery. The sensitivity, specificity, and accuracy of ultrasound and MR imaging were calculated and compared. RESULTS: A total of 195 patients were enrolled in this study. Of these, 184 had arthroscopically confirmed anterosuperior acetabular labral tear. The sensitivity, specificity, positive predictive value (PPV), negative predictive value, and accuracy by ultrasound were, respectively, 68.5%, 81.8%, 98 4%, 13.4%, and 69.2%, retrospectively. For MR imaging, the sensitivity, specificity, PPV, negative predictive value, and accuracy were 84.8%, 63.6%, 97.5%, 20.0%, and 83.6%, respectively. CONCLUSIONS: Although ultrasound had a slightly lower sensitivity for detecting anterosuperior acetabular labral tear, it had a higher specificity and PPV than MR imaging. With the advantages of being inexpensive, relatively quick, noninvasive, and having dynamic evaluation, ultrasound could be used as a feasible method to evaluate anterosuperior acetabular labral tear. LEVEL OF EVIDENCE: Level IV, case series.

The Extension-Thickness-Damage (ETD) score: a pre-operative hip MR arthrography-based classification to predict type of labrum surgery.

INTRODUCTION: Hip magnetic resonance arthrography (MRA) is the pre-operative imaging modality of choice in patients with labral damage, with several classifications of labral tears having been reported based on MRA findings. Nevertheless, none of the available classification systems allows the surgeon to predict before surgery how a labral tear could be treated. Our purpose was to develop a new MRA-based scoring system of labral tears to predict before surgery the treatment option more suitable for labral tears. MATERIALS AND METHODS: Forty-seven patients (29 males and 18 females; mean age: 35.9 ± 12.4) performed hip MRA for suspicious of femoroacetabular impingement and were afterwards subjected to arthroscopic treatment. Two musculoskeletal radiologists reviewed all pre-operative examinations and provided the Extension-Thickness-Damage score for each patient, based on Extension of tear, Thickness of labrum, and type of Damage. Chondral lesions grading was based on the arthroscopic findings according to Konan classification. For statistical purposes, patients were divided into two groups, depending on the type of treatment: labral repair or debridement. Mann-Whitney U, Chi-square, receiver operator curves, and Cohen kappa statistics were used. RESULTS: 35/47 underwent repair, while 12/47 were debrided. In both groups, the median chondral damage was grade III, with no significant differences (p = 0.439). The median Extension-Thickness-Damage score in the repair group (6) was significantly lower (p < 0.001) than that in the debridement group (8). The highest diagnostic performance (area under the curve) of Extension-Thickness-Damage was 0.819. The inter-observer agreement was substantial in the evaluation of Extension (k = 0.626) and Thickness (k = 0.771), and almost perfect for Damage (k = 0.827). Higher scores of Extension and Thickness were more frequently associated with debridement (p < 0.001; p = 0.0016, respectively), with no significant differences on the basis of Damage parameter (p = 0.284). CONCLUSIONS: The MRA-based Extension-Thickness-Damage score could represent a helpful pre-operative tool, expressing the extent of the damage and its reparability before arthroscopy.

Arthroscopic Reconstruction of the Irreparable Acetabular Labrum: A Match-controlled Study.

PURPOSE: To report clinical outcomes of arthroscopic labral reconstruction in the hip at minimum 2-year follow-up in comparison to a pair-matched labral repair group. METHODS: Patients were included in this study if they underwent labral reconstruction during hip arthroscopy and had minimum 2-year follow-up data available. Exclusion criteria were active workers' compensation claims or previous ipsilateral hip surgery or conditions. Reconstruction patients were matched 1:2 to patients that underwent arthroscopic labral repair but otherwise met all inclusion and exclusion criteria. Matching criteria were age within 5 years, sex, body mass index within 5, same capsular treatment, and whether there was chondral damage of Outerbridge grade II or greater. Three patient-reported outcome (PRO) measures and visual analog scale (VAS) for pain were recorded preoperatively and at a minimum of 2 years postoperatively. International Hip Outcome Tool and patient satisfaction were also collected at latest follow-up. RESULTS: Thirty-four reconstruction patients were matched to 68 repair patients. There were no significant differences in age (P = .941), sex (P > .999), body mass index (P = .935), or any other demographics between groups. A statistically significant increase was seen in PROs for both the reconstruction group (Modified Harris Hip Score, P = .002; Hip Outcome Score - Sports Subscale, P<.001; Non-arthritic Hip Score, P<.001) and the repair group (Modified Harris Hip Score, P<.001; Hip Outcome Score - Sports Subscale, P < .001; Non-arthritic Hip Score, P<.001) at minimum 2-year follow-up. Significant decrease was shown for VAS for both groups (reconstruction VAS, P<.001; repair, P<.001) at minimum 2-year follow-up. There were no significant differences in rates of postoperative complications (P>.999), secondary arthroscopy (P>.999), or conversion to total hip arthroplasty (P = .728) between groups. CONCLUSIONS: Arthroscopic labral reconstruction is associated with significant improvement in PROs and a low incidence of secondary surgery within 2-year follow-up. Improvements in PROs, VAS, patient satisfaction, and incidence of secondary procedures were comparable to a match control treated with labral repair. Although there were no differences shown in the 2 groups with respect to complication rate, secondary arthroscopy, or conversion to total hip arthroplasty, the study was not powered to compare these outcome parameters. Based on this evidence, either labral repair or reconstruction may be selected depending upon the clinical scenario. LEVEL OF EVIDENCE: Level III; retrospective comparative study.

Acetabular All-Suture Anchor for Labral Repair: Incidence of Intraoperative Failure due to Pullout.

PURPOSE: To report on the incidence and features of intraoperative anchor pullout in a consecutive series of patients undergoing arthroscopic labral repair of the hip. METHODS: Over an 18-month period, 434 consecutive cases underwent labral repair by a single surgeon with a particular anchor system. The following data were recorded: (1) age and gender of all cases; (2) number of anchors used; (3) number of cases in which intraoperative anchor failure occurred; (4) number of anchors that failed; and (5) age and gender of those cases in which anchor failure occurred. Failures were reported for 3-month intervals. One patient underwent repair with an alternative anchor system during this time period and was excluded. RESULTS: Mean age was 34.2 (14-71) years with 180 males and 254 females. A total of 2,007 anchors were used, averaging 4.6 per case (1-8). Thirty-three anchors pulled out among 30 patients, representing a 1.6% incidence among all anchors. Mean age among pullouts was 37.8 (17-54) years with 11 males and 19 females. There was no difference compared with patient population in which no anchor pulled: mean 33.9 (14-71) years (P = .085) with 169 males and 235 females (P = .578). Pullouts were evenly distributed over the 3-month intervals (4, 4, 6, 6, 5, 8). Pullout was mostly due to failure to securely imbed the anchor in bone. Only 2 were known to pull out in the presence of being securely seated in bone. CONCLUSIONS: These data support that the security of this particular all-suture anchor at implantation is exceptionally reliable for a single experienced surgeon, and there is no demonstrable learning curve. LEVEL OF EVIDENCE: Level IV, retrospective review of a case series.

Dynamic ulnar impaction syndrome in tennis players: report of two cases / Síndrome do impacto ulnocarpal dinâmico em tenistas: relato de dois casos

ABSTRACT In this report, two tennis players with symptoms of ulnar impaction syndrome are reviewed. Both players have neutral ulnar variance. These cases represent dynamic ulnar impaction syndrome, when the impact between ulna and carpus occurs during conditions of pronated grip. The literature and the treatment of these two cases are discussed.

RESUMO O relato apresenta os casos de dois tenistas portadores de dor no bordo ulnar do carpo com sinais de impacto no semilunar. Ambos são portadores de ulna neutra. Esses casos representam uma entidade denominada síndrome do impacto ulnocarpal dinâmico na qual ocorre o impacto entre a cabeça da ulna e o carpo em situação de pronação com punho fechado durante a atividade física. A literatura e o tratamento dos dois casos são discutidos no artigo.

Unravelling the Role of Mechanical Stimuli in Regulating Cell Fate During Osteochondral Defect Repair.

We have previously developed a computational mechanobiological model to explore the role of substrate stiffness and oxygen availability in regulating stem cell fate during spontaneous osteochondral defect repair. This model successfully simulated many aspects of the regenerative process, however it was unable to predict the spatial patterns of endochondral bone and fibrocartilaginous tissue formation observed during the latter stages of the repair process. It is hypothesised that this was because the mechanobiological model did not consider the role of tissue strain in regulating specific aspects of chondrocyte differentiation. To test this, our mechanobiological model was updated to include rules whereby intermediate levels of octahedral shear strain inhibited chondrocyte hypertrophy, while excessively high octahedral shear strains resulted in the formation of fibrocartilage. This model was used to simulate spontaneous osteochondral defect repair, where it correctly predicted the experimentally observed patterns of bone formation. Overall the results suggest that oxygen availability regulates chondrogenesis and endochondral ossification during the early phases of osteochondral defect repair, while direct mechanical cues play a greater role in regulating chondrocyte differentiation during the latter stages of this process. In particular, these results suggest that an appropriate loading regime can assist in promoting the development of stable hyaline cartilage during osteochondral defect repair.

The Hip in Ice Hockey: A Current Concepts Review.

Ice hockey is a fast, physical sport with unique associated biomechanical demands often placing the hip in forced and repetitive supraphysiological ranges of motion. Ice hockey players commonly endure and are sidelined by nebulous groin injury or hip pain. Underlying causes can be chronic or acute and extra-articular, intra-articular, or "hip-mimicking." This article serves to review common hip-related injuries in ice hockey. For each, we define the particular condition; comment on risk factors and preventive strategies; discuss key historical, physical examination, and imaging findings; and finally, suggest nonoperative and/or operative treatment plans.

Spectrum of Injury to Posterior Glenoid Labral Complex With Emphasis on Diffuse Labral Tears.

The posterior glenoid labrum has numerous surrounding structures and any of them can undergo derangement. It is prudent to consider the posterior glenoid labrum complex (PGLC) as a whole rather than simply the labral tissue in isolation when evaluating magnetic resonance imaging (MRI) of the shoulder. The PGLC contains the posterior capsulolabral junction, posterior capsule (posteroinferiorly , the posterior band of the inferior glenohumeral ligament), posterior chondro-osseous junction, posterior chondrolabral junction, posterior glenoid bone, posterior glenoid subchondral bone, posterior glenoid cartilage, posterior labrum, synovial fold (variably seen), and posterior glenoid periosteum (or periosteal sleeve). Noninvasive MRI techniques are the mainstay in evaluating PGLC injury with or without the use of intra-articular gadolinium contrast agents. When using the PGLC model, a spectrum of pathology can be stratified.

Return to play after treatment of shoulder labral tears in professional hockey players.

OBJECTIVES: Shoulder labral injuries in professional hockey players are often treated surgically to minimize missed ice time. Previous studies have shown that post-operative outcomes in these players are favorable, although they have not specifically focused on athletic performance and time to return to sport. Our objective was to report time to return to play and post-operative on-ice performance metrics after shoulder labral repair in professional ice hockey players. METHODS: We performed a retrospective review of the clinical records of all professional hockey players (NHL) who underwent arthroscopic shoulder labral repair by one surgeon between January 2004 and December 2008. Operative data included labral injury type, number of anchors used, concomitant pathology, and complications. Player information included position, shooting hand, games played before and after surgery, date of return to play (RTP), time on ice (TOI) and shots on goal before and after surgery. Paired sample t-test and independent sample t-tests or their non-parametric equivalents were used to compare pre-and post-operative player performance variables using the SPSS statistical package. RESULTS: Eleven NHL Players (13 shoulders) were included in the study. The average follow-up was 19.4 months (12.7-37 months, SD 7.4) and average age was 29 years (20-36, SD 5.1). Of the 13 shoulders, there were various types of labral tears including three Bankart tears, three superior (SLAP) tears, two posterior tears, three combined anterior/posterior tears, and two panlabral tears. All 11 players returned to play (RTP) after surgery at an average time of 4.3 months. There were no significant differences between time to RTP for players with dominant-sided injuries (4.2 months) and non-dominant injuries (4.6 months), p = 0.632. Five players had increased time-on-ice (TOI) and five players had decreased TOI after surgery, though this difference was not significant (p = 0.3804). On average, the shots on goal per game played (SOG/GP) decreased by 0.13 after surgery which was not significantly different (p = 0.149). There were no post-operative complications observed. CONCLUSION: Professional ice hockey players can safely return to full competition at an average of 4.3 months after arthroscopic shoulder labral repair without significant decline in player performance.

Navigating the Alphabet Soup of Labroligamentous Pathology of the Shoulder.

Because of the widespread use of eponyms and acronyms to describe labroligamentous findings in the shoulder, interpreting shoulder magnetic resonance imaging reports can be challenging. A summary of the appearance of these lesions on shoulder magnetic resonance images can help the orthopedic surgeon to understand these entities as imaging findings and to determine the appropriate treatment for patients with shoulder injuries.

SLAP lesions: a treatment algorithm.

Tears of the superior labrum involving the biceps anchor are a common entity, especially in athletes, and may highly impair shoulder function. If conservative treatment fails, successful arthroscopic repair of symptomatic SLAP lesions has been described in the literature particularly for young athletes. However, the results in throwing athletes are less successful with a significant amount of patients who will not regain their pre-injury level of performance. The clinical results of SLAP repairs in middle-aged and older patients are mixed, with worse results and higher revision rates as compared to younger patients. In this population, tenotomy or tenodesis of the biceps tendon is a viable alternative to SLAP repairs in order to improve clinical outcomes. The present article introduces a treatment algorithm for SLAP lesions based upon the recent literature as well as the authors' clinical experience. The type of lesion, age of patient, concomitant lesions, and functional requirements, as well as sport activity level of the patient, need to be considered. Moreover, normal variations and degenerative changes in the SLAP complex have to be distinguished from "true" SLAP lesions in order to improve results and avoid overtreatment. The suggestion for a treatment algorithm includes: type I: conservative treatment or arthroscopic debridement, type II: SLAP repair or biceps tenotomy/tenodesis, type III: resection of the instable bucket-handle tear, type IV: SLAP repair (biceps tenotomy/tenodesis if >50 % of biceps tendon is affected), type V: Bankart repair and SLAP repair, type VI: resection of the flap and SLAP repair, and type VII: refixation of the anterosuperior labrum and SLAP repair.

Anatomy of the capsulolabral complex and rotator interval related to glenohumeral instability.

The glenohumeral joint with instability is a common diagnosis that often requires surgery. The aim of this review was to present an overview of the anatomy of the glenohumeral joint with emphasis on instability based on the current literature and to describe the detailed anatomy and anatomical variants of the glenohumeral joint associated with anterior and posterior shoulder instability. A review was performed using PubMed/MEDLINE using key words: Search terms were "glenohumeral", "shoulder instability", "cadaver", "rotator interval", "anatomy", and "anatomical study". During the last decade, the interest in both arthroscopic repair techniques and surgical anatomy of the glenohumeral ligament (superior, middle, and inferior), labrum, and rotator interval has increased. Understanding of the rotator interval and attachment of the inferior glenohumeral ligament on the glenoid or humeral head have evolved significantly. The knowledge of the detailed anatomy and anatomical variations is essential for the surgeon in order to understand the pathology, make a correct diagnosis of instability, and select proper treatment options. Proper understanding of anatomical variants can help us avoid misdiagnosis. Level of evidence V.

Bipolar bone defect in the shoulder anterior dislocation.

In the anterior shoulder instability with glenoid bone loss among 25 % or more of the inferior glenoid diameter (inverted-pear glenoid), the consensus of recent authors is that glenoid bone grafting (Latarjet procedure) should be performed. The engaging Hill-Sachs lesion has been recognized as a risk factor for recurrent anterior shoulder instability. We have developed a method using radiographic and arthroscopic studies and the concept of the glenoid track to determine whether a Hill-Sachs lesion will engage the anterior glenoid rim, whether or not there is concomitant anterior glenoid bone loss. If the Hill-Sachs lesion engages, it is called an "off-track" Hill-Sachs lesion; if it does not engage, it is an "on-track" lesion. On the basis of our quantitative method, we have developed a treatment paradigm with specific surgical criteria for all patients with anterior shoulder instability (first dislocation or recurrent dislocation), both with and without bipolar bone loss.

Clinical outcome of arthroscopic SLAP repair: conventional vertical knot versus knotless horizontal mattress sutures.

PURPOSE: Arthroscopic repair of type II superior labrum anterior to posterior (SLAP) tears yields variable results. In this study, the clinical outcomes of arthroscopic knotless horizontal mattress repair were compared to those of conventional vertical knot repair. METHODS: Forty-six patients treated arthroscopically for isolated SLAP lesions were assessed. Forty-one of those patients underwent follow-up evaluations for a minimum of 2 years: 21 received vertical knot (group 1), while 20 received horizontal mattress (group 2). In group 1, an anchor was inserted at the superior glenoid. After relaying the sutures, knotting over the labral tissue was performed. In group 2, two strands were passed through the labrum and fixed into the glenoid with a bioabsorbable knotless anchor. Functional scores were evaluated preoperatively and at the final follow-up assessment. A visual analogue scale (VAS) for pain and range of motion (ROM) were assessed preoperatively, 2 months postoperatively and at the last follow-up visit. RESULTS: There were no significant differences in functional scores between groups (n.s.). However, external rotation at the side, internal rotation at abduction and total ROM were better in group 2 at the last follow-up visit. At 2 months postoperatively, the VAS for pain and ROM of internal rotation at abduction were better in group 2. CONCLUSION: At the final assessment, there were no significant differences in functional scores between the two groups. However, external rotation at the side, internal rotation at abduction and total ROM were better in group 2. LEVEL OF EVIDENCE: Case-control study, Level III.

External rotation and active supination CT arthrography for the postoperative evaluation of type II superior labral anterior to posterior lesions.

PURPOSE: To evaluate the effectiveness of external rotation and active supination CT arthrography in postoperative evaluation by comparing it with neutral CT arthrography and analyzing its agreement with postoperative clinical results after the repair of type II superior labral anterior to posterior (SLAP) lesions. MATERIALS AND METHODS: A total of 25 patients who had undergone CT arthrography in neutral, external rotation and active supination position at least 1 year after the arthroscopic repair of SLAP lesions were enrolled. Two radiologists independently evaluated the status of the repaired SLAP lesions with neutral CT arthrography and then with external rotation and active supination CT arthrography. RESULTS: Five patients had residual symptoms and positive findings upon SLAP-specific examinations. Agreements between the presence of symptoms and radiologic diagnoses based on neutral CT arthrography were insignificant for reader 1 (κ = 0.138, p = n.s.) and significant for reader 2 (κ = 0.328, p = 0.027). However, agreements were highly significant in the analysis following the evaluation of external rotation and active supination CT arthrography for both readers (κ = 0.694, p < 0.001 in reader 1; κ = 0.783, p < 0.001 in reader 2). CONCLUSIONS: The presence of contrast-filled gaps between the labrum and glenoid on neutral CT arthrography after SLAP repair is frequent with satisfactory clinical outcomes. Gaps without additional widening upon external rotation and active supination CT arthrography may suggest postoperatively stable biceps anchors, so this new method could minimize the overdiagnosis of recurrent SLAP lesions. Additional gap widening on external rotation and active supination CT arthrography could be related to a true recurrent SLAP lesion and the symptoms of the patients. LEVEL OF EVIDENCE: Case series, Level IV.