Results of Arthroscopic Revision Rotator Cuff Repair for Failed Open or Arthroscopic Repair: A Prospective Multicenter Study on 100 Cases.

Background: Retears after rotator cuff repair (RCR) have been associated with poor clinical results. Meaningful data regarding the role of arthroscopic revision RCR are sparse thus far.

Purpose/hypothesis: To investigate results after arthroscopic revision RCR.

TGF-β3 Loaded Electrospun Polycaprolacton Fibre Scaffolds for Rotator Cuff Tear Repair: An in Vivo Study in Rats.

Biological factors such as TGF-β3 are possible supporters of the healing process in chronic rotator cuff tears. In the present study, electrospun chitosan coated polycaprolacton (CS-g-PCL) fibre scaffolds were loaded with TGF-β3 and their effect on tendon healing was compared biomechanically and histologically to unloaded fibre scaffolds in a chronic tendon defect rat model. The biomechanical analysis revealed that tendon-bone constructs with unloaded scaffolds had significantly lower values for maximum force compared to native tendons.

Possibilities and limitations of electrospun chitosan-coated polycaprolactone grafts for rotator cuff tear repair.

Acute and chronic rotator cuff tears remain challenging for therapy. A wide range of therapeutic approaches were developed but re-tears and postoperative complications occur regularly. Especially in elderly people, the natural regeneration processes are decelerated, and graft materials are often necessary to stabilize the tendon-to-bone attachment and to improve the healing process.

In vivo analysis of vascularization and biocompatibility of electrospun polycaprolactone fibre mats in the rat femur chamber.

In orthopaedic medicine, connective tissues are often affected by traumatic or degenerative injuries, and surgical intervention is required. Rotator cuff tears are a common cause of shoulder pain and disability among adults. The development of graft materials for bridging the gap between tendon and bone after chronic rotator cuff tears is essentially required.

Reverse shoulder arthroplasty for fracture sequelae: Clinical outcome and prognostic factors.

Background: The reverse total shoulder arthroplasty (RTSA) is a common therapy for the fracture sequelae (FS) of the proximal humerus. The aim of this study was to show the short and midterm clinical outcome of the RTSA for FS and to identify prognostic factors.

Methods: Data from 46 patients with chronic FS who underwent RTSA were analysed.

[Options in joint-preserving surgical treatment of osteoarthritis].

Background: The treatment of glenohumeral arthritis represents a major challenge in highly active younger patients. In these patients, an endoprosthetic treatment often achieves only unsatisfactory results with a limited lifetime of the implant.

Objectives: The aim of the study was to identify joint-preserving therapies for glenohumeral arthritis.

Arthroscopic posterior bone block stabilization-early results of an effective procedure for the recurrent posterior instability.

Purpose: In the current study the clinical outcome of an arthroscopic posterior bone block augmentation in combination with a posterior capsular repair was investigated.

Methods: Twenty-four shoulders (18 patients) with unidirectional posterior shoulder instability were treated with an arthroscopic posterior bone block and capsular reconstruction. The mean follow up period was 26 months.

The effect of rotator cuff malreduction on tendon tension: an evaluation of a custom-made digital tensiometer clamp.

Introduction: Rotator cuff tears are common and good-to-excellent clinical outcome is reported after subsequent repair. However, the retear rate of rotator cuff repairs has been shown to be as high as 20%. The reasons for retear seem to be multifactorial, mainly comprised by mechanical and biological aspects.

First Metatarsophalangeal Joint Arthrodesis: A Retrospective Comparison of Crossed-screws, Locking and Non-Locking Plate Fixation with Lag Screw.

Background: Locking plate fixation is increasingly used for first metatarsophalangeal joint (MTP-I) arthrodesis. There are still few comparable clinical data regarding this procedure. In this study we aimed to compare the clinical and radiographical outcomes of crossed-screws, locking and non-locking plate fixation with lag screw for first metatarsophalangeal joint arthrodesis.

rhBMP-2 in an injectable Gelfoam carrier enhances consolidation of the distracted callus in a sheep model.

Background: A major problem associated with distraction osteogenesis is the long time required for consolidation.

Objective: The goal of this study was to determine whether a percutaneous injection of recombinant human bone morphogenetic protein-2 (rhBMP-2) in a Gelfoam carrier would enhance bone consolidation following distraction.

Methods: A unilateral tibial osteotomy combined with external stabilization was performed in 14 adult sheep.

αBSM failed as a carrier of rhBMP-2 to enhance bone consolidation in a sheep model of distraction osteogenesis.

Purpose: One of the problems associated with callus distraction is a long time period needed for consolidation of the newly formed bone. The goal of this study was to determine whether percutaneous injections of rhBMP 2 in αBSM would enhance bone consolidation.

Methods: A unilateral tibial osteotomy combined with external stabilization was performed in 20 adult sheep.

Anterior stability of the reverse shoulder arthroplasty depending on implant configuration and rotator cuff condition.

Introduction: The aim of this study was to investigate the stabilizing influence of the rotator cuff as well as the importance of glenosphere and onlay configuration on the anterior stability of the reverse total shoulder replacement (RTSR).

Materials And Methods: A reverse total shoulder replacement was implanted into eight human cadaveric shoulders, and biomechanical testing was performed under three conditions: after implantation of the RTSR, after additional dissection of the subscapularis tendon, and after additional dissection of the infraspinatus and teres minor tendon. Testing was performed in 30° of abduction and three rotational positions: 30° internal rotation, neutral rotation, and 30° external rotation.

Implant impingement during internal rotation after reverse shoulder arthroplasty. The effect of implant configuration and scapula anatomy: A biomechanical study.

Background: Internal rotation after reverse shoulder arthroplasty is essential to perform fundamental daily living activities. The purpose of this study was to examine the impact of anatomical and implant related factors on impingement-free internal rotation of the glenohumeral joint.

Methods: CT-scans of 13 human shoulder specimens with implanted reverse shoulder prostheses were carried out and scapula neck length, lateral pillar angle, and implantation height of the metaglene were measured.

Biomechanical evaluation of inferior scapula notching of reverse shoulder arthroplasty depending on implant configuration and scapula neck anatomy.

Purpose: The presence of inferior scapula notching is significantly affected by the anatomy the scapula and can be influenced by the glenosphere design and position and the onlay type.

Materials And Methods: A biomechanical study was undertaken with 13 human shoulder specimens in a robot-assisted shoulder simulator. Inferior scapula contact during adduction of the humerus was detected using a contact pressure film.

Total Versus Hemiarthroplasty for Glenohumeral Arthritis According to Preoperative Glenoid Erosion.

Clinical studies on primary osteoarthritis have shown better results of total shoulder arthroplasty (TSA) compared to hemiarthroplasty (HA) regarding the function, revision rate and postoperative pain relief. However, a clear recommendation for implantation of TSA or HA, depending on the glenoid type of erosion, does not exist. The aim of the study was to compare the results of TSA and HA with respect to the preoperative glenoid type.

Humeral surface replacement for osteoarthritis.

Background And Purpose: Humeral resurfacing has shown promising results for osteoarthritis, but revisions for glenoid erosion have been reported frequently. We investigated the hypothesis that preoperative glenoid wear and postoperative progress of glenoid erosion would influence the clinical outcome.

Methods: We reviewed 61 resurfacing hemiarthroplasties (55 patients) for primary osteoarthritis.

Results of arthroscopic partial repair of large retracted rotator cuff tears.

Purpose: To evaluate the midterm results of partial rotator cuff repair using the Constant score and the acromiohumeral radiographic measurement.

Methods: Thirty-eight patients with a mean age of 65 years and a large retracted rotator cuff tear (at least 2 tendons) were included in the study. Patients underwent clinical examination, standard radiography, and isometric strength testing at a mean follow-up of 47 months.

The Phosphate Source Influences Gene Expression and Quality of Mineralization during In Vitro Osteogenic Differentiation of Human Mesenchymal Stem Cells.

For in vitro differentiation of bone marrow-derived mesenchymal stem cells/mesenchymal stromal cells into osteoblasts by 2-dimensional cell culture a variety of protocols have been used and evaluated in the past. Especially the external phosphate source used to induce mineralization varies considerably both in respect to chemical composition and concentration. In light of the recent findings that inorganic phosphate directs gene expression of genes crucial for bone development, the need for a standardized phosphate source in in vitro differentiation becomes apparent.

Arthroscopic posterior shoulder stabilization with an iliac bone graft and capsular repair: a novel technique.

Several surgical approaches have been described for the treatment of recurrent posterior shoulder instability. Many authors have performed posterior bone block procedures with good results not only in the presence of glenoid bone loss or dysplasia but also in the case of capsular hyperlaxity and poor soft-tissue quality. Open techniques often require an extensive approach with the disadvantage of a poor cosmetic result and possible insufficiency of the deltoid muscle.

Biomechanical comparison of open and arthroscopic Latarjet procedures.

Purpose: To biomechanically compare the effectiveness of the standard open and arthroscopic techniques of the Latarjet procedure to address a critical anterior glenoid defect in combination with a capsular insufficiency.

Methods: Translation testing of 12 human cadaveric shoulder specimens was performed in a robot-assisted setup under 3 different conditions: (1) intact/vented shoulder joint, (2) combined anterior glenoid bone and capsular defect, and (3) open and arthroscopic Latarjet procedures. Testing was performed for each condition in 2 test positions: 60° of glenohumeral abduction with neutral rotation (ABD position) and 60° of abduction and external rotation (ABER position).

Short and midterm results of reverse shoulder arthroplasty according to the preoperative etiology.

Background: Reverse shoulder arthroplasty (RSA) has shown promising results for cuff tear arthropathy but the indication has been extended to fracture sequelae and revision shoulder arthroplasty with different preconditions. Further, the clinical relevance of inferior scapular notching for different etiologies is uncertain. Our hypothesis was that preoperative etiology as well as the occurrence of scapular notching would significantly influence the clinical outcome.

Repetitive recombinant human bone morphogenetic protein 2 injections improve the callus microarchitecture and mechanical stiffness in a sheep model of distraction osteogenesis.

Evidence suggests that recombinant human bone morphogenetic protein 2 (rhBMP-2) increases the mechanical integrity of callus tissue during bone healing. This effect may be either explained by an increase of callus formation or a modification of the trabecular microarchitecture. Therefore the purpose of the study was to evaluate the potential benefit of rhBMP-2 on the trabecular microarchitecture and on multidirectional callus stiffness.

The influence of superior labrum anterior to posterior (SLAP) repair on restoring baseline glenohumeral translation and increased biceps loading after simulated SLAP tear and the effectiveness of SLAP repair after long head of biceps tenotomy.

Hypothesis: Biomechanical studies have shown increased glenohumeral translation and loading of the long head biceps (LHB) tendon after superior labrum anterior to posterior (SLAP) tears. This may explain some of the typical clinical findings, including the prevalence of humeral chondral lesions, after SLAP lesions. The first hypothesis was that SLAP repair could restore the original glenohumeral translation and reduce the increased LHB load after SLAP lesions.

Suprapectoral or subpectoral position for biceps tenodesis: biomechanical comparison of four different techniques in both positions.

Hypothesis: The aim of this study was to compare different techniques for tenodesis of the long head of biceps tendon (LHB) in the suprapectoral and subpectoral position to test the hypothesis that using shorter screws at the subpectoral position would achieve a similar primary ultimate failure load (UFL) as the longer screws at the suprapectoral position, that both types of tenodesis screws achieve comparable UFL, and that knotless suture anchor techniques can be performed at the subpectoral position in cortical bone and reach a UFL similar to tenodesis screws.

Methods: On 42 fresh frozen human cadavers divided into 6 groups, 4 different techniques for LHB tenodesis were performed localized 10 mm and 50 mm, respectively, distal to the entrance of the bicipital groove. Two techniques with tenodesis screws (Bio-Tenodesis screw, Biceptor) and 2 with knotless suture anchors (Bio-SwiveLock, Footprint PK) were tested.