Effect of different decellularization protocols on reendothelialization with human cells for a perfused renal bioscaffold of the rat.

BACKGROUND: Scaffolds for tissue engineering can be received by whole organ decellularization while maintaining the site-specific extracellular matrix and the vascular tree. One among other decellularization techniques is the perfusion-based method using specific agents e.g. SDS for the elimination of cellular components. While SDS can disrupt the composition of the extracellular matrix and impair the adherence and growth of site-specific cells there are indications that xenogeneic cell types may benefit from protein denaturation by using higher detergent concentrations. The aim of this work is to investigate the effect of two different SDS-concentrations (i.e. 0.66% and 3%) on the ability of human endothelial cells to adhere and proliferate in an acellular rat kidney scaffold. MATERIAL AND METHODS: Acellular rat kidney scaffold was obtained by perfusion-based decellularization through the renal artery using a standardized protocol including SDS at concentrations of 0.66% or 3%. Subsequently cell seeding was performed with human immortalized endothelial cells EA.hy 926 via the renal artery. Recellularized kidneys were harvested after five days of pressure-controlled dynamic culture followed sectioning, histochemical and immunohistochemical staining as well as semiquantitative analysis. RESULTS: Efficacy of decellularization was verified by absence of cellular components as well as preservation of ultrastructure and adhesive proteins of the extracellular matrix. In semiquantitative analysis of recellularization, cell count after five days of dynamic culture more than doubled when using the gentle decellularization protocol with a concentration of SDS at 0.66% compared to 3%. Detectable cells maintained their endothelial phenotype and presented proliferative behavior while only a negligible fraction underwent apoptosis. CONCLUSION: Recellularization of acellular kidney scaffold with endothelial cells EA.hy 926 seeded through the renal artery benefits from gentle decellularization procedure. Because of that, decellularization with a SDS concentration at 0.66% should be preferred in further studies and coculture experiments.

"Functional outcomes and MRI-based tendon healing after (antero-) superior rotator cuff repair among patients under 50 years: retrospective analysis of traumatic versus non-traumatic rotator cuff tears".

BACKGROUND: Rotator cuff tears among patients under 50 years either result from an adequate trauma or are considered non-traumatic due to work-related or athletic overuse. The impact of these different mechanisms on postoperative functional outcomes and tendon healing has not yet been fully understood. Therefore, it was the purpose of this study to investigate the influence of etiology of (antero-)superior rotator cuff tears on postoperative outcomes and the healing rates after arthroscopic rotator cuff repair in a young patient population. METHODS: Patients under 50 years who underwent arthroscopic rotator cuff repair between 2006-2017 for an anterosuperior rotator cuff tear with a minimum follow up of 24 months were included in this study. Revision surgeries or reconstructive concomitant procedures other than long head of the biceps tenodesis were excluded. Patients were divided into two groups according to the etiology of their rotator cuff tear (traumatic vs. non-traumatic). Demographic and outcome scores including the American Shoulder and Elbow Surgeons (ASES) score, the Constant Score (CS), bilateral strength measurements and postoperative tendon integrity evaluated on magnetic resonance imaging (MRI) were assessed and compared between both groups. RESULTS: The mean follow up for this study was 55.6 months (24 - 158). Twenty-one patients (50.0%) had a traumatic RCT and 21 patients (50.0%) had a non-traumatic tear. Outcome scores did not differ significantly between groups. Strength measurements of the supraspinatus revealed significantly decreased force of the affected side as opposed to the contralateral side (p = 0.001), regardless of etiology. Retear rates were similar in both groups (37.5% and 33.3%, p = n.s.). Cuff integrity at follow-up was not predictive of superior scores or strength. CONCLUSION: Surgical treatment of traumatic and non-traumatic RCT yields good clinical results in patients under the age of 50. The etiology of the rotator cuff tear did not significantly affect postoperative outcomes or healing rates. About one third of the patients suffered from a retear postoperatively, however retears were not predictive of inferior outcomes at midterm follow-up. STUDY DESIGN: Level III. TRIAL REGISTRATION: Retrospectively registered.

All-suture anchors for distal biceps tendon repair: a preliminary outcome study.

INTRODUCTION: The aim of this study was to retrospectively evaluate the clinical outcome of double intramedullary all-suture anchors' fixation for distal biceps tendon ruptures. MATERIALS AND METHODS: A retrospective case series of patients who underwent primary distal biceps tendon repair with all-suture anchors was conducted. Functional outcome was assessed at a minimum follow-up of at 12 months based on the assessments of the Mayo Elbow Performance Score (MEPS), Andrews-Carson Score (ACS), Quick Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH), and the Visual Analog Scale (VAS) for pain. Maximum isometric strength test for flexion and supination as well as postoperative range of motion (ROM) were determined for both arms. RESULTS: 23 patients treated with all-suture anchors were assessed at follow-up survey (mean age 56.5 ± 11.4 years, 96% male). The follow-up time was 20 months (range Q0.25-Q0.75, 15-23 months). The following outcome results were obtained: MEPS 100 (range Q0.25-Q0.75, 100-100); ACS 200 (range Q0.25-Q0.75, 195-200); QuickDASH 31 (range Q0.25-Q0.75, 30-31); VAS 0 (range Q0.25-Q0.75, 0-0). The mean strength compared to the uninjured side was 95.6% (range Q0.25-Q0.75, 80.9-104%) for flexion and 91.8 ± 11.6% for supination. There was no significant difference in ROM or strength compared to the uninjured side and no complications were observed in any patient. CONCLUSION: Distal biceps tendon refixation using all-suture anchors provides good-to-excellent results in terms of patient-reported and functional outcome. This repair technique appears to be a viable surgical option, although further long-term results are needed. LEVEL OF EVIDENCE: Level IV (case series).

Validation of a novel 3-dimensional classification for degenerative arthritis of the shoulder.

INTRODUCTION: A novel three-dimensional classification to comprehensively describe degenerative arthritis of the shoulder (DAS) was recently published by our group. The purpose of the present work was to investigate intra- and interobserver agreement as well as validity for the three-dimensional classification. MATERIALS AND METHODS: Preoperative computed tomography (CT) scans of 100 patients who had undergone shoulder arthroplasty for DAS were randomly selected. Four observers independently classified the CT scans twice, with an interval of 4 weeks, after prior three-dimensional reconstruction of the scapula plane using a clinical image viewing software. Shoulders were classified according to biplanar humeroscapular alignment as posterior, centered or anterior (> 20% posterior, centered, > 5% anterior subluxation of humeral head radius) and superior, centered or inferior (> 5% inferior, centered, > 20% superior subluxation of humeral head radius). Glenoid erosion was graded 1-3. Gold-standard values based on precise measurements from the primary study were used for validity calculations. Observers timed themselves during classification. Cohen's weighted κ was employed for agreement analysis. RESULTS: Intraobserver agreement was substantial (κ = 0.71). Interobserver agreement was moderate with a mean κ of 0.46. When the additional descriptors extra-posterior and extra-superior were included, agreement did not change substantially (κ = 0.44). When agreement for biplanar alignment alone was analyzed, κ was 0.55. The validity analysis reached moderate agreement (κ = 0.48). Observers took on average 2 min and 47 s (range 45 s to 4 min and 1 s) per CT for classification. CONCLUSIONS: The three-dimensional classification for DAS is valid. Despite being more comprehensive, the classification shows intra- and interobserver agreement comparable to previously established classifications for DAS. Being quantifiable, this has potential for improvement with automated algorithm-based software analysis in the future. The classification can be applied in under 5 min and thus can be used in clinical practice.

Reliable Clinical and Sonographic Outcomes of Subpectoral Biceps Tenodesis Using an All-Suture Anchor Onlay Technique.

PURPOSE: To evaluate the clinical outcomes and structural integrity of primary subpectoral biceps tenodesis using an all-suture anchor onlay technique for long head of the biceps (LHB) tendon pathology. METHODS: We conducted a retrospective case series with prospectively collected data of patients who underwent primary, isolated subpectoral biceps tenodesis with a single all-suture anchor onlay fixation between March 2017 and March 2019. Outcomes were recorded at a minimum follow-up of 12 months based on assessments of the American Shoulder and Elbow Surgeons (ASES) score, LHB score, and elbow flexion strength and supination strength measurements. The integrity of the tenodesis construct was evaluated using ultrasound. RESULTS: Thirty-four patients were available for clinical and ultrasound examination at a mean follow-up of 18 ± 5 months. The mean ASES score significantly improved from 51.0 ± 14.2 points preoperatively to 89.8 ± 10.5 points postoperatively (P < .001). The minimal clinically important difference for the ASES score was 8.7 points, which was exceeded by 31 patients (91.2%). The mean postoperative LHB score was 92.2 ± 8.3 points. Regarding subcategories, an average of 47.2 ± 6.3 points was reached for "pain/cramps"; 26.4 ± 6.1 points, "cosmesis"; and 18.6 ± 2.6 points, "elbow flexion strength." Both elbow flexion strength and supination strength were similar compared with the nonoperated side (P = .169 and P = .210, respectively). In 32 patients, ultrasound examination showed an intact tenodesis construct, whereas 2 patients (5.9%) sustained failure of the all-suture anchor fixation requiring revision. CONCLUSIONS: Primary subpectoral biceps tenodesis using an all-suture anchor onlay technique for pathology of the LHB tendon provides reliable clinical results and a relatively low failure rate (5.9%). LEVEL OF EVIDENCE: Level IV, case series.

High return to sports and return to work rates after anatomic lateral ankle ligament reconstruction with tendon autograft for isolated chronic lateral ankle instability.

PURPOSE: To evaluate clinical outcomes as well as return to sports (RTS) and return to work (RTW) rates following anatomic lateral ankle ligament reconstruction with a tendon autograft for chronic lateral ankle instability (CLAI) in a high-risk population, and to compare these outcome parameters between patients having received a gracilis tendon autograft (GT) and free split peroneus brevis tendon (PBT) autograft. METHODS: Twenty-eight consecutive patients, who were diagnosed with CLAI, presenting with ≥ 1 risk factor (ligamentous hyperlaxity, insufficient substance of native ligament and/or high-demand athlete), who underwent ankle ligament reconstruction with a tendon autograft between January 2011 and December 2018, were included in this retrospective study. At 63.7 ± 28.0 months (24-112), 23 patients with a mean age of 29.7 ± 10.9 years were available for follow-up. The Karlsson Score, the Foot and Ankle Outcome Score (FAOS), the Tegner Activity Scale and the visual analog scale (VAS) for pain were collected at a minimum follow-up of 24 months. RTS and RTW were evaluated by questionnaire. A subgroup analysis with regard to the graft used for ankle ligament reconstruction (GT versus PBT) was performed. RESULTS: Patients reported a Karlsson score of 82.1 ± 17.5 (37-100), a FAOS score of 87.8 ± 8.4 (73-99), a median Tegner activity scale of 5.0 (IQR 4-6) and a VAS for pain of 0.5 ± 0.9 (0-4) at rest and of 2.0 ± 2.1 (0-7) during activities at final follow-up. Postoperatively, 96% of patients had returned to sports after 8.3 ± 6.2 months. All patients (100%) had returned to work at 3.5 ± 5.7 (0-24) months, with 87% reporting an equal or improved working ability compared to that preoperatively. Postoperatively, exercise hours per week were significantly reduced compared to preoperatively in patients with a split PBT (n = 12; 13.0 ± 12.9 to 5.6 ± 6.4 h, p = 0.038) autograft as opposed to patients with a GT autograft (n = 11; 13.1 ± 8.7 to 12.4 ± 7.1 h, n.s.). No other group differences were observed. CONCLUSION: Good patient-reported outcomes as well as excellent RTS and RTW rates can be achieved in high-risk patients undergoing ankle ligament reconstruction with a tendon autograft for CLAI. These results may be helpful in preoperatively managing patients' expectations regarding sports- and work-related outcomes and provide tangible data on the expectable time frame of the individual return to sports and work trajectory. LEVEL OF EVIDENCE: IV.

Definition of the terms "acute" and "traumatic" in rotator cuff injuries: a systematic review and call for standardization in nomenclature.

BACKGROUND: Although of high relevance for clinical decision making, there exists no consensus throughout the literature of the terms "acute" and "traumatic" used in the classification of rotator cuff tears. With differing definitions, the comparability of outcome studies may be limited. The aim was to provide a detailed systematic review of the definitions used in the literature and present a suggestion for a standardization in nomenclature based on the findings. METHODS: Four different internet databases were searched in February 2020 using the terms ("acute" OR "traumatic" OR "trauma" OR "athlete" OR "young") AND ("rotator cuff tears" OR "rotator cuff tear" OR "rotator cuff" OR "rotator cuff rupture" OR "supraspinatus" OR "infraspinatus" OR "subscapularis" OR "teres minor"). Prospective, retrospective, cohort and case-control studies as well as case series were included. Systematic reviews, cadaveric or laboratory studies and studies on non-traumatic or non-acute rotator cuff tears were excluded. RESULTS: The literature search conducted 10,349 articles of which 10,151 were excluded based on the title, 119 based on the abstract and 33 based on the manuscript. A total of 46 studies were finally included for review and subsequently analyzed. Overall, there exists no consensus neither on the term "acute" nor on "traumatic" in the context of rotator cuff tears in the literature. The time span for acute injuries ranged between 2 weeks and 6 months. For traumatic injuries, only 20% of the selected studies described a specific and adequate injury mechanism in combination with adequate imaging. CONCLUSION: The term "acute" should be reserved for RCT showing muscle edema, wavelike appearance of the central part of the torn tendon and joint effusion, which typically requires adequate imaging within 2 weeks from trauma. Repair of acute tears should occur within 8 weeks from trauma to benefit from possibly superior biological healing capacities. The term "traumatic" should be used for a sudden onset of symptoms in a previously asymptomatic patient, triggered by an adequate trauma, e.g., a fall on the retroverted arm with an axial cranioventral force or a traumatic shoulder dislocation.

[Patellofemoral inlay implants-an innovation in patellofemoral joint arthroplasty?] / Patellofemorale Inlay-Implantate ­ ein Fortschritt in der patellofemoralen Endoprothetik?

Isolated arthrosis of the patellofemoral joint is a rare and complex disease. After conservative therapy has been exhausted, the orthopedist has various soft-tissue and bone reconstructive procedures as well as cartilage regenerative procedures at his hands. In cases of failed or unsatisfactory therapy, patellofemoral arthroplasty continues to be controversially discussed as an alternative therapy. A closer look at these studies reveals promising results with the correct indication and patient selection. The different prosthesis designs provide good postoperative results while considering general and specific risks. The current generation of patellofemoral inlay prostheses shows high patient satisfaction with significant improvements in knee function and pain relief in mid-term outcomes. However, a relatively high revision rate must be considered.

[Primary (idiopathic) shoulder stiffness : Definition, disease progression, epidemiology and etiology]. / Primäre (idiopathische) Schultersteife : Definition, Krankheitsverlauf, Epidemiologie und Ätiologie.

Shoulder stiffness is characterized by restriction of the active and passive movement of the glenohumeral joint. The stiffness is ultimately caused by fibrosis and the resulting contracture of the glenohumeral joint capsule and its ligaments; however, the term stiff shoulder is only a descriptive umbrella term that must be further defined as the course of the disease and the recommended treatment are decisively influenced by the cause of the shoulder stiffness. Primary shoulder stiffness, also known as idiopathic shoulder stiffness or "frozen shoulder", must be distinguished from various forms of secondary shoulder stiffness and often occurs in three stages, which can all last for several months to years: the initial "freezing phase", followed by a "frozen phase" and finally a "thawing phase". Although primary shoulder stiffness is a frequent pathological alteration with an prevalence of 2-5% in the general population, the exact etiology remains largely unknown; however, there is consensus throughout the literature that certain systemic pathologies, such as diabetes mellitus are associated with a higher incidence of primary shoulder stiffness.

[Current approach in the follow-up treatment of joint-preserving operations on the knee joint in German-speaking countries]. / Aktuelles Vorgehen in der Nachbehandlung gelenkerhaltender Operationen am Kniegelenk im deutschsprachigen Raum.

INTRODUCTION: Postoperative follow-up after joint-preserving knee surgery involves conventional physiotherapy as well as other approaches and devices such as CPM and CAM splints, TENS devices, BFR exercise, prehabilitation, and digital health applications. The aim of this survey was to investigate current standards, trends and control methods in postoperative care to identify fields of concern and to compare them with the current literature. MATERIAL AND METHODS: We conducted a structured anonymous online survey of specialists in orthopaedics and trauma surgery listed by the German-speaking Society for Arthroscopy and Joint Surgery (AGA). The questionnaire included 36 closed-ended questions on the follow-up of joint-preserving surgery of the knee joint. RESULTS: Questionnaires from 528 participants with long-term professional experience (86.6% with more than 10 years) were analysed. Standardised post-treatment schemes are used by 97.2% and their evidence is estimated to be high (59.1%) / very high (14.8%). Problems of rehabilitation are seen in 10-20% of cases by 87.3% (persistent muscular atrophy 30.9%). After reconstructive surgery, CPM splints (70.1%), CAM splints (42.1%), orthoses (85.0%) and TENS devices (40.0%) are prescribed. More potent approaches for the treatment of postoperative muscle deficits are desired by 89.4%. BFR exercise is known by 41.7% and is used regularly by 8%. Communication with treating physiotherapists is infrequent (written: 27.5%). Digital rehabilitation management would be supported by 83.3%; 22.7% are not aware of digital health applications. 87.9% of participants believe that prehabilitation can affect postoperative outcomes. CONCLUSION: Follow-up of knee joint-preserving surgeries is usually standardised and regularly reviewed for up-to-date evidence. The evidence for recommendations made is considered high. Orthoses are usually used after reconstructive surgery, persistent muscle atrophy is a major problem, BFR training is only known to a limited extent, and there is currently a lack of standardised training protocols. Communication with physiotherapists needs to be improved. Digital rehabilitation management is rarely used but would be supported by the majority of surgeons.

The Morphology of the Acromioclavicular Joint Does Not Influence the Postoperative Outcome Following Acute Stabilization-A Case Series of 81 Patients.

Purpose: To specifically evaluate the influence of the acromioclavicular (AC)-joint morphology on the outcome after arthroscopically assisted coracoclavicular (CC) stabilization surgery with suspensory fixation systems and to investigate whether an additional open AC-joint reduction and AC cerclage improves the clinical outcome for patients with certain morphologic AC-joint subtypes. Methods: Patients with an acute acromioclavicular joint injury, who underwent arthroscopically assisted CC stabilization with suspensory fixation systems with or without concomitant AC cerclage between January 2009 and June 2017 were identified and included in this retrospective cohort analysis. AC-joint morphology was assessed on preoperative radiographs and categorized as "flat" or "non-flat" ("oblique"/"curved") subtypes. After a minimum of 2 years of follow-up, postoperative Single Assessment Numeric Evaluation (SANE), American Shoulder and Elbow Surgeons (ASES), and visual analog scale (VAS) scores for pain were collected. A subgroup analysis of clinical outcomes depending on the surgical technique and morphological subtype of the AC joint was performed. Results: Eighty-one patients (95% male, mean age 35 ± 12 years) could be included at a mean follow-up of 57 ± 14 months. Radiographic assessment of AC-joint morphology showed 24 (30%) cases of flat type, 38 (47%) cases of curved type, and 19 (23%) cases of oblique morphology. Postoperatively, no clinically significant difference could be detected after the treatment of AC joint injury via CC stabilization with or without concomitant AC cerclage (VASrest: P = .067; VASmax: P = .144, ASES: P = .548; SANE: P = .045). No clinically significant differences were found between the surgical techniques for the flat morphologic subtype (VASrest: P = .820; VASmax: P = .251; SANE: P = .104; ASES: P = .343) or the non-flat subtype (VASres: P = .021; VASmax: P = .488; SANE: P = .243, ASES: P = .843). Conclusions: In arthroscopically assisted AC stabilization surgery with suspensory fixation systems for acute AC-joint injury, the AC-joint morphology did not influence the postoperative outcome, independent of the surgical technique. No clinical benefit of performing an additional horizontal stabilization could be detected in our collective at mid-term follow-up. Level of Evidence: Level IV, therapeutic case series.