Converting to reverse shoulder arthroplasty from primary anatomic shoulder arthroplasty and fracture hemiarthroplasty: a radiographic and clinical outcome analysis at 8-years.

INTRODUCTION: Revision shoulder arthroplasty can be challenging. One of the main considerations for surgeons is the type of implant that was placed in the initial surgery. Anatomic shoulder arthroplasty (ASA) is used for cases of osteoarthritis as well as for fractures of the humeral head. Hemiarthroplasty can be used for complex proximal humerus fractures. The purpose of this study is to determine whether there is a difference in clinical and radiographic outcomes between patients that failed primary fracture hemiarthroplasty (FHA), or ASA for osteoarthritis and then required reoperation with a conversion to reverse shoulder arthroplasty (RSA). METHODS: Patients with failed anatomic shoulder replacement, who had undergone conversion to RSA, were enrolled after a mean follow-up of 107 (85-157) months. Two different groups, one with failed ASA implanted for osteoarthritis and one with failed FHA, were created. At follow-up patients were assessed with standard radiographs and clinical outcome scores. RESULTS: Twenty-nine patients (f = 17, m = 12; 51%) suffered from a failed ASA (Group A), while the remaining 28 patients (f = 21, m = 74; 49%) had been revised due to a failed FHA (Group B). Patients of Group B had a poorer Constant score (Group A: 60 vs. Group B: 46; p = 0.02). Abduction (Group A: 115° vs. Group B: 89°; p = 0.02) was worse after conversion of a failed FHA to RSA in comparison to conversions of failed ASA. The mean bone loss of the lateral metaphysis was higher in patients with failed FHA (Group A: 5 mm vs. Group B: 20 mm; p = 0.0). CONCLUSION: The initial indication for anatomic shoulder arthroplasty influences the clinical and radiological outcome after conversion to RSA. Conversion of failed FHA to RSA is related to an increased metaphyseal bone loss, decreased range of motion and poorer clinical outcomes when compared to conversions of failed ASA implanted for osteoarthritis. LEVEL OF EVIDENCE: III Retrospective Cohort Comparison Study.

The arthroscopic treatment of anterior shoulder instability with glenoid bone loss shows similar clinical results after Latarjet procedure and iliac crest autograft transfer.

PURPOSE: Recurrent anterior shoulder instability caused by critical bone loss of the glenoid is a challenging condition for shoulder surgeons. The purpose of this prospective multicenter trial was to compare the arthroscopic transfer of the coracoid process (Latarjet procedure) with the arthroscopic reconstruction of the glenoid using iliac crest autografts. METHODS: A prospective multi-center trial was performed in nine orthopaedic centres in Austria, Germany and Switzerland between July 2015 and August 2021. Patients were prospectively enrolled and received either an arthroscopic Latarjet procedure or an arthroscopic iliac crest graft transfer. Standardized follow-up after 6 months and mimimum 24 months included range of motion, Western Ontario stability index (WOSI), Rowe score and subjective shoulder value (SSV). All complications were recorded. RESULTS: 177 patients (group Latarjet procedure: n = 110, group iliac crest graft: n = 67) were included in the study. WOSI (n.s.), SSV (n.s.) and Rowe score (n.s.) showed no difference at final follow-up. 10 complications were seen in group Latarjet procedure and 5 in group iliac crest graft; the frequency of complications did not differ between the two groups (n.s.). CONCLUSION: The arthrosopic Latarjet procedure and arthroscopic iliac crest graft transfer lead to comparable results regarding clinical scores, frequency of recurrent dislocations and complication rates. LEVEL OF EVIDENCE: Level II.

Bone tunnel placement influences shear stresses at the coracoid process after coracoclavicular ligament reconstruction: a finite element study and radiological analysis.

INTRODUCTION: Coracoid fractures after arthroscopic treatment of acromioclavicular (AC) joint separations lead to poor clinical outcomes. In this study, different configurations of bone tunnels in the lateral clavicle and coracoid were examined concerning the amount of stress induced in the coracoid. METHODS: An authentic 3D finite element model of an ac joint was established. Three 2.4 mm bone tunnels were inserted in the lateral clavicle, which were situated above, medially and laterally of the coracoid. Then, two 2.4 mm bone tunnels were inserted in the latter, each simulating a proximal and a distal suture button position. Von Mises stress analyses were performed to evaluate the amount of stress caused in the coracoid process by the different configurations. Then, a clinical series of radiographs was examined, the placement of the clavicle drill hole was analyzed and the number of dangerous configurations was recorded. RESULTS: The safest configuration was a proximal tunnel in the coracoid combined with a lateral bone tunnel in the clavicle, leading to an oblique traction at the coracoid. A distal bone tunnel in the coracoid and perpendicular traction as well as a proximal tunnel in the coracoid with medial traction caused the highest stresses. Anatomical placement of the clavicle drill hole does lead to configurations with smaller stresses. CONCLUSION: The bone tunnel placement with the smallest amount of shear stresses was found when the traction of the suture button was directed slightly lateral, towards the AC joint. Anatomical placement of the clavicle drill hole alone was not sufficient in preventing dangerous configurations. LEVEL OF EVIDENCE: Controlled laboratory study.

Sonographic Measurement of Dynamic Horizontal Instability in Acromioclavicular Joint Instability: Description of a Simple Technique and Correlation to Radiographic Parameters.

OBJECTIVE: Dynamic horizontal instability is considered to be the main reason for poor outcome after treatment for acromioclavicular (AC) joint instability. In this study, we describe a simple technique to quantify this pathology via sonography. METHODS: Thirty-six shoulders from 18 patients with ac joint instabilities were examined using modified Alexander views and a standardized sonographic examination. On the Alexander views, overlap of acromion and clavicle (OLAC), glenoid center to posterior clavicle distance (GCPC), and lateral extension (LE) were measured. Afterwards, the results were analyzed and compared with sonography. Posterior translation of the clavicle and the difference of translation between healthy and injured shoulder were evaluated. RESULTS: The mean age of the patients was 39 ± 14 years (range 19-61 years). We included 4 (22%) Rockwood type 3, 1 (6%) Rockwood type 4, and 13 (72%) Rockwood type 5 lesions. Four (22%) patients were female and 14 (78%) male patients. Posterior clavicle translation of the injured shoulder correlated strongly between OLAC and sonography (r = -0.514, P = .029), and the difference of translation between healthy and injured shoulder correlated very strongly between LE and sonography (r = 0.737, P < .001). CONCLUSION: The sonographic measurement technique for horizontal instability presented in this work could help detect horizontal instabilities. While the observation of dynamic horizontal displacement is a strength of this technique, measurements are hindered in cases of high coracoclavicular distances. LEVEL OF EVIDENCE: Level III-retrospective cohort study.

Treatment of proximal humerus fractures using reverse shoulder arthroplasty: do the inclination of the humeral component and the lateral offset of the glenosphere influence the clinical outcome and tuberosity healing?

INTRODUCTION: The employment of reverse shoulder arthroplasty for dislocated proximal humerus fractures of elderly patients becomes increasingly relevant. The standard inclination angle of the humeral component was 155°. Lately, there is a trend towards smaller inclination angles of 145° or 135°. Additionally, there has been an increased focus on the lateralization of the glenosphere. This retrospective comparative study evaluates clinical and radiological results of patients treated for proximal humerus fractures by reverse shoulder arthroplasty with different inclination angles of the humeral component, which was either 135° or 155°. Additionally, a different lateral offset of the glenosphere, which was either 0 mm or 4 mm, was used. METHODS: For this retrospective comparative analysis, 58 out of 66 patients treated by reverse total shoulder arthroplasty for proximal humerus fractures were included. The minimum follow-up was 24 months. Thirty (m = 3, f = 27; mean age 78 years; mean FU 35 months, range 24-58 months) were treated with a standard 155° humeral component and a glenosphere without lateral offset (group A), while 28 patients (m = 2, f = 26; mean age 79 years; mean FU 30 months, range 24-46 months) were treated with a 135° humeral component and a glenosphere with a 4 mm lateral offset (group B). We determined range of motion, Constant score, and the American Shoulder and Elbow Surgeons Shoulder score as clinical outcomes and evaluated tuberosity healing as well as scapula notching. RESULTS: Neither forward flexion (A = 128°, B = 121°; p = 0.710) nor abduction (A = 111°, B = 106°; p = 0.327) revealed differences between the groups. The mean Constant Score rated 63 in group A, while it was 61 in group B (p = 0.350). There were no differences of the ASES Score between the groups (A = 74, B = 72; p = 0.270). There was an increased risk for scapula notching in group A (47%) in comparison to group B (4%, p = 0.001). Healing of the greater tuberosity was achieved in 57% of group A and in 75% of group B (p = 0.142). The healing rate of the lesser tuberosity measured 33% in group A and 71% in group B (p = 0.004). CONCLUSIONS: Both inclination angles of the humeral component are feasible options for the treatment of proximal humerus fractures in elderly patients. Neither the inclination angle nor the lateral offset of the glenosphere seem to have a relevant influence on the clinical outcome. The healing rate of the lesser tuberosity was higher in implants with a decreased neck-shaft angle. There is an increased risk for scapula notching, if a higher inclination angle of the humeral component is chosen. LEVEL OF EVIDENCE: III. Retrospective comparative study.

A biomechanical comparison of steel screws versus PLLA and magnesium screws for the Latarjet procedure.

INTRODUCTION: The fixation of the coracoid process onto the glenoid is an important step of the Latarjet procedure, and implant-associated complications are a relevant and severe problem. This study compares the fixation strength and failure mode of two biodegradable materials with stainless-steel screws. METHODS: 24 Fresh-frozen cadaveric scapulae were divided into three groups of equal size and received a coracoid transfer. Cadavers were matched according to their bone mineral density (BMD). In group 1, small-fragment screws made of stainless steel were used. In the second group, magnesium screws were used, and in the third group, screws consisted of polylactic acid (PLLA). A continuously increasing sinusoidal cyclic compression force was applied until failure occurred, which was defined as graft displacement relative to its initial position of more than 5 mm. RESULTS: At 5-mm displacement, the axial force values showed a mean of 374 ± 92 N (range 219-479 N) in group 1 (steel). The force values in group 2 (magnesium) had a mean of 299 ± 57 N (range 190-357 N). In group 3 (PLLA), failure occurred at 231 ± 83 N (range 109-355 N). The difference between group 1 (steel) and group 2 (magnesium) was not statistically significant (P = 0.212), while the difference between group 1 (steel) and group 3 (PLLA) was significant (P = 0.005). CONCLUSION: Stainless-Steel screws showed the highest stability. However, all three screw types showed axial force values of more than 200 N. Stainless steel screws and PLLA screws showed screw cut-out as the most common failure mode, while magnesium screws showed screw breakage in the majority of cases. EVIDENCE: Controlled laboratory study.

Treating cuff tear arthropathy by reverse total shoulder arthroplasty: do the inclination of the humeral component and the lateral offset of the glenosphere influence the clinical and the radiological outcome?

PURPOSE: Reverse total shoulder arthroplasty is widely used for the treatment of cuff tear arthropathy. Standard implants consist of a humeral component with an inclination angle of 155° and a glenosphere without lateral offset. Recently, lower inclination angles of the humeral component as well as lateralized glenospheres are implanted to provide better rotation of the arm and to decrease the rate of scapular notching. This study investigates the clinical and radiological results of a standard reverse total shoulder in comparison with an implant with an inclination angle of 135° in combination with a 4 mm lateralized glenosphere in context of cuff tear arthropathy. MATERIAL AND METHODS: For this retrospective comparative analysis 42 patients treated by reverse total shoulder arthroplasty for cuff tear arthropathy were included. Twenty-one patients (m = 11, f = 10; mean age 76 years; mean follow-up 42 months) were treated with a standard 155° humeral component and a standard glenosphere with caudal eccentricity (group A), while twenty-one patients (m = 5, f = 16; mean age 72 years; mean follow-up 34 months) were treated with a 135° humeral component and 4 mm lateral offset of the glenosphere (group B). At follow-up patients of both groups were assessed with plain X-rays (a.p. and axial view), Constant Score, adjusted Constant Score, the subjective shoulder value and the range of motion. RESULTS: The clinical results were similar in both groups concerning the Constant Score (group A = 56.3 vs. group B = 56.1; p = 0.733), the adjusted CS (group A = 70.4% vs. group B = 68.3%; p = 0.589) and the SSV (group A = 72.0% vs. group B = 75.2%; p = 0.947). The range of motion of the operated shoulders did not differ significantly between group A and group B: Abduction = 98° versus 97.9°, p = 0.655; external rotation with the arm at side = 17.9° versus 18.7°, p = 0.703; external rotation with the arm positioned in 90° of abduction = 22.3° versus 24.7°, p = 0.524; forward flexion = 116.1° versus 116.7°, p = 0.760. The rate of scapular notching was higher (p = 0.013) in group A (overall: 66%, grade 1: 29%, grade 2: 29%, grade 3: 10%, grade 4: 0%) in comparison to group B (overall: 33%, grade 1: 33%, grade 2: 0%, grade 3: 0%, grade 4: 0%). Radiolucency around the humeral component was detected in two patients of group B. Stress shielding at the proximal humerus was observed in six patients of Group A (29%; cortical thinning and osteopenia in zone M1 and L1) and two patients of group B (10%; cortical thinning and osteopenia in zone M1 and L1). Calcifications of the triceps origin were observed in both groups (group A = 48% vs. group B = 38%). CONCLUSION: Theoretically, a lower inclination angle of the humeral component and an increased lateral offset of the glenosphere lead to improved impingement-free range of motion and a decreased rate of scapular notching, when compared to a standard reverse total shoulder implant. This study compared two different designs of numerous options concerning the humeral component and the glenosphere. In comparison to a standard-fashioned implant with a humeral inclination of 155° and a standard glenosphere, implants with a humeral inclination angle of 135° and a 4 mm lateralized glenosphere lead to comparable clinical results and rotatory function, while the rate of scapular notching is decreased by almost 50%. While the different implant designs did not affect the clinical outcome, our results indicate that a combination of a lower inclination angle of the humeral component and lateralized glenosphere should be favored to reduce scapular notching. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Cement augmentation of an angular stable plate osteosynthesis for supracondylar femoral fractures - biomechanical investigation of a new fixation device.

BACKGROUND: Implant anchorage in highly osteoporotic bone is challenging, since it often leads to osteosynthesis failure in geriatric patients with supracondylar femoral fractures. Cementation of screws is presumed to prevent such osteosynthesis failure. This study aimed to investigate the effect of a newly designed, cementable fenestrated condylar screw for plate fixation in a biomechanical setting. METHODS: Eight pairs of osteoporotic cadaver femora with an average age of 77 years, ranging between 62 and 88 years, were randomly assigned to either an augmented or a non-augmented group. In both groups an instable 33-A3 fracture according to the AO / OTA classification was fixed with an angular stable locking plate. All right samples received a cement augmentation of their fenestrated condylar screws with calcium phosphate bone cement (CPC). Mechanical testing was performed at a load to failure mode by cyclic axial loading, using a servohydraulic testing machine. RESULTS: With a mean of 2475 N (95% CI: 1727-3223 N), the pressure forces resulting in osteosynthesis failure were significantly higher in specimen with cemented condylar screws as compared to non-cemented samples (1875 N (95% CI: 1320-2430 N)) (p = 0.024). In both groups the deformation of the constructs, with the distal screws cutting through the condylar bone, were the most frequent cause for failure. Analysis of axial stiffness (p = 0.889) and irreversible deformity of the specimens revealed no differences between the both groups (p = 0.161). No cement leakage through the joint line or the medial cortex was observed. CONCLUSION: Based on the present study results, the newly introduced, cementable condylar screw could be an encouraging feature for the fixation of supracondylar femoral fractures in patients with reduced bone quality in terms of load to failure accuracy of the cement application.

Pullout strength and failure mode of industrially manufactured and self-made all-suture anchors: a biomechanical analysis.

BACKGROUND: This study presents a new technique for assembling an all-suture anchor from existing medical products. The biomechanical characteristics of this self-made anchor (SMA) are compared with those of an industrially manufactured all-suture anchor. METHODS: The SMAs were made from established medical products (FiberWire #2 and 2-mm FiberTape; Arthrex, Naples, FL, USA). Pretesting was performed in biphasic polyurethane foam blocks. In the next step, 10 SMAs and 10 industrially made anchors (IMAs; 1.8-mm double-loaded Y-Knot Flex all-suture anchor; ConMed Linvatec, Largo, FL, USA) were applied with an insertion tool and tested in fresh porcine femora using a servohydraulic testing system, with a preload of 10 N and a displacement rate of 12.5 mm/s. Pullout strength and failure mode were recorded. RESULTS: The mean load at failure in the foam blocks was 459 ± 124 N in the SMA group and 538 ± 83 N in the IMA group. In porcine bone, failure occurred at 461 ± 102 N in the SMA group and 431 ± 135 N in the IMA group. The differences in pullout strength between the 2 types of anchor were not statistically significant, either in the foam blocks (P = .17) or in porcine bone (P = .62). CONCLUSION: A handmade all-suture anchor using 2 high-strength sutures woven into a 2-mm strip of high-strength tape did not show statistically different failure loads in polyurethane foam or in porcine metaphyseal bone in comparison with a commercially produced double-loaded all-suture anchor. The principal mode of failure in porcine bone in both groups was anchor pullout.

Anatomic considerations for arthroscopic glenoid reconstruction using iliac crest grafts: a radiologic study.

BACKGROUND: Arthroscopic glenoid reconstruction using autografts is an advanced procedure that requires experience and preparation. Knowledge about anatomic pitfalls is therefore important to establish well-positioned portals and prevent neurovascular damage. METHODS: We included 43 computed tomography scans from 43 patients. The distance between the tip of the coracoid process and a perpendicular line representing the anteroinferior glenoid was measured. From these results an anteroinferior working portal was designed, and the angulation needed for screw insertion to fixate a hypothetical graft was measured. In a second step, 9 patients underwent magnetic resonance imaging scans 34 ± 10 months after glenoid reconstruction, and the distance between the screw approach path and the neurovascular bundle was measured. RESULTS: In the analyzed scans, average defect size was 23%, and the coracoid process to the anteroinferior glenoid distance was 32 ± 7 mm. We thus hypothesized that a corridor 20 to 30 mm inferior to the coracoid process would be the ideal position for a working portal. Through this portal, 85% of screws could be applied with 0° to 30° angulation. When the postoperative scans were analyzed, the distance from the neurovascular bundle showed an average of 26 ± 6 mm for the superior screw and 21 ± 5 mm for the inferior screw. CONCLUSIONS: The ideal distance between the coracoid process and an anteroinferior working portal is 32 mm. Having established the portal, instruments should not be inserted pointing in a medial direction of the coracoid process due to the proximity of the neurovascular bundle.

All-arthroscopic glenoid reconstruction by iliac crest bone graft transfer does not affect structural integrity and 3-dimensional volume of the subscapularis muscle.

AIM: The subscapularis muscle is an important active stabilizer of the glenohumeral joint. For this radiological study, we investigated if its radiological integrity is affected after arthroscopic glenoid reconstruction. In the technique used, an autologous iliac crest graft is transported through the rotator interval, and the graft is fixed via an antero-inferior portal with compression screws. METHODS: 3 women and 6 men (mean age 31 ± 9 years, min 21, max 46 years) who had a preoperative glenoid deficit of 23% ± 6% (min 13%, max 29%) were included. In a follow-up after an interval of 34 months (min 19, max 50), MRI scans were performed on both shoulders. With ITK-SNAP, a 3D reconstruction software, the volume of the subscapularis muscle in the injured and contralateral shoulder was measured. In addition, signal intensity ratios (PSI) (infraspinatus muscle / cranial subscapularis muscle and infraspinatus muscle / caudal subscapularis muscle) were analyzed and the width of the cranial and caudal portions as well as the length of the subscapularis muscle in the parasagittal plane were determined. RESULTS: The 3D volume showed no difference between operated and healthy shoulders (p = 0.07), neither did PSI ratios (infraspinatus muscle / cranial subscapularis muscle: p = 1.00, infraspinatus muscle / caudal subscapularis muscle: p = 1.00). In the parasagittal plane, length (p = 0.09) and cranial width (p = 0.23) did not differ. However, the width of the lower muscle was increased in injured shoulders (p = 0.02). CONCLUSION: In this cohort, no relevant volume loss could be found after arthroscopic glenoid reconstruction. However, a greater width of the lower muscle portion could be identified in the parasagittal plane as a possible indication of scarring.

Bone grafts used for arthroscopic glenoid reconstruction restore the native glenoid anatomy.

PURPOSE: Recurrent anterior instability of the glenohumeral joint is a demanding condition, especially in cases of glenoid bone loss. Various treatment options have been described, such as arthroscopic grafting techniques and the Latarjet procedure. In this study, the degree to which an arthroscopically applied iliac crest graft restores the glenoid anatomy was evalutated. METHODS: Nine patients (three women and six men) with an average age of 31 ± 9 years (21-46 years) who were treated with an arthroscopic iliac crest graft technique were included in this study. After a mean follow up of 34 ± 10 months (19-50 months) after the procedure, MRI scans of both shoulders were performed and the glenoid width, Glenoid Index (GI), Pixel Signal intensity (PSI), thickness of the tissue covering the articular aspect of the graft, inclination, version, concavity and balance stability angle were measured. RESULTS: All scans showed the cultivation of tissue on the graft, which visually resembled the cartilage of the native ipsilateral glenoid. Additionally, reshaping of the graft to repair the glenoid configuration could be observed. Glenoid width (p = 0.022) and GI (p < 0.001) increased significantly through surgery. The tissue examined on the graft showed a significant pixel intensity gap (p = 0.017) but comparable thickness (n.s.) in relation to native cartilage. The remaining parameters did not differ significantly between both shoulders. CONCLUSION: In the cohort presented, iliac crest grafts were able to restore the glenoid configuration, and the glenoid was re-shaped to its native contour. Additionally, cartilage-like scar tissue with similar thickness as healthy cartilage was formed on the articular side of the graft. These results suggest that glenoid reconstruction is not only important for prevention of recurrence, but also for restoration of the native glenoid anatomy. LEVEL OF EVIDENCE: Level III-retrospective cohort study.

Standardised pre-operative diagnostics and treatment of peripheral arterial disease reduce wound complications in geriatric ankle fractures.

PURPOSE: The aim of this study was to evaluate a standardised algorithm to assess and treat impaired limb perfusion prior to surgical fixation of geriatric ankle fractures and determine the prevalence of peripheral arterial disease (PAD) in geriatric patients presenting with ankle fractures. METHODS: Eighty-four patients >65 years pre-operatively diagnosed and treated according to an algorithm (study group) were compared with 84 patients diagnosed and treated before the algorithm was introduced (control group). RESULTS: In 14 patients of the study group, clinical noninvasive examination revealed signs of relevant PAD, which was confirmed with computed tomographic angiography (CTA) in nine patients, all of whom had successful angioplasty prior to surgical fixation of the ankle fracture. In three of these patients, PAD had previously been diagnosed. After standardised diagnostics and treatment of malperfusion, a significantly reduced overall and, particularly, wound complication rate was found. CONCLUSION: PAD is an underdiagnosed condition in geriatric patients presenting with ankle fractures. This study underlines the relevance of limb perfusion for adequate wound healing in geriatric ankle fractures. Therefore, special attention should be paid to diagnose and-if indicated-optimise limb perfusion prior to surgical fixation of geriatric ankle fractures.

Mid-term clinical results of an arthroscopic glenoid rim reconstruction technique for recurrent anterior shoulder instability.

INTRODUCTION: Glenoid bone loss in recurrent anterior instability of the shoulder needs to be addressed to restore joint stability. Over the last years, several arthroscopic methods have been described to treat this condition. However, no clinical mid-term results have been presented for arthroscopic iliac crest bone grafting procedures. METHODS: We included 32 patients with significant glenoid bone loss and repetitive dislocations of the shoulder who were treated in our shoulder unit with a previously described all-arthroscopic reconstruction technique. All patients filled out a questionnaire evaluating repetitive dislocations, consumption of pain medicine, Constant Score (CS, adapted to age and gender), activities of daily living (ADL), visual analogue scale for pain (VAS) as well as the Western Ontario Shoulder Instability Index (WOSI). Additionally, all complications were recorded. RESULTS: After a mean follow-up of 42 months, three traumatic dislocations had been observed. With an ADL of 25 points (95% CI 24-27), a WOSI of 71% (95% CI 65-76) and CS of 87 points (95% CI 82-92), our patients showed good functional results. The VAS result for pain was 2.1 (95% CI 1.5-2.6). No patient reported the regular usage of pain medicine related to the shoulder instability at final follow-up. CONCLUSION: The all-arthroscopic glenoid reconstruction using iliac crest grafts shows good functional results with a recurrence rate of 9%. At final follow-up 42 months after surgery, our patients showed low pain levels and acceptable complications.

Mapping of glenoid bone loss in recurrent anterior shoulder instability: is there a particular deficit pattern?

BACKGROUND: Glenoid bone loss in recurrent anterior shoulder instability is a challenging problem for shoulder surgeons, and knowledge about the anatomy of glenoid deficits is scarce. In this study, we tried to evaluate the pattern of this pathology. METHODS: Our analysis included 44 shoulders from 44 patients with recurrent anterior shoulder instability accompanied by a clinically relevant glenoid bone loss. The defect size, the localization of the inferior defect edge, and the defect angle were measured, and osseous landmarks were identified. An en face view on 2-dimensional computed tomography scans of each patient was fitted onto a template to create a deficit map for small (<23%) and large (>23%) defects. RESULTS: The study cohort consisted of 9 women and 35 men with a mean age of 33 ± 11 years at the date of the scan. The defect size and localization of the inferior defect edge showed significant differences between both groups, indicating a more posterior position of larger defects. The defect angle, however, showed no significant difference between small and large defects. Both groups showed a vertical defect pattern. CONCLUSION: The osseous glenoid deficit in recurrent anterior shoulder instability shows a vertical pattern with no remarkable differences between small and large defects. This finding can influence biomechanical models as well as surgical reconstruction.

The osseous morphology of nondegenerated shoulders shows no side-related differences in elderly patients: an analysis of 102 computed tomography scans.

BACKGROUND: A precise understanding of glenohumeral anatomy is required to optimize preoperative planning in shoulder joint arthroplasty, which is difficult in the presence of degenerative disease. In unilateral disease, the contralateral shoulder can be used as a representation of normal anatomy; however, intrasubject differences in shoulder morphology have not been investigated. METHODS: A retrospective study of all patients aged >65 years who received whole body computed tomography at our trauma center from 2010 through 2014 was conducted. Right and left shoulder computed tomography scans were examined, and the following anatomic parameters were measured: humeral head diameter in anteroposterior and axial views, glenoid diameter in anteroposterior and axial views, glenoid surface, scapula neck depth, neck-shaft angle, glenoid inclination, glenoid/head ratio, and glenoid version. Patients with inadequate scan quality, osseous lesions, pre-existing anatomic abnormality, or metallic implant at the shoulder region and significant osteoarthritis were excluded. RESULTS: The study analyzed 102 shoulders of 51 patients. Mean age was 71.4 ± 8.2 years. Humeral head and glenoid diameters, scapula neck depth (right, 36 ± 8 mm; left, 36 ± 7 mm; P = .684), glenoid/head ratio (right, 0.6 ± 0.1; left, 0.6 ± 0.0; P = .961), and glenoid surface (right, 790 ± 152 mm(2); left, 754 ± 134 mm(2); P = .215) showed no significant side-related differences. In addition, no significant difference was found regarding the neck-shaft angle (P = .211) and glenoid anteversion or retroversion (right, 65% [n = 33] anteversion and 35% [n = 18] retroversion; left, 69% [n = 35] anteversion and 31% [n = 16] retroversion; P = .417). CONCLUSION: There are no significant side-dependent differences in the osseous anatomy of the glenohumeral joint. In patients with unilateral shoulder degeneration, the contralateral shoulder can provide reference values during the planning of shoulder replacement surgery.

Age-dependent variation of glenohumeral anatomy: a radiological study.

PURPOSE: Profound knowledge of variations in shoulder anatomy is gaining relevance in daily clinical work. In our study, we examine age-dependent variations of glenohumeral parameters in healthy individuals. METHODS: In this analysis, 774 severely injured patients who received a whole-body computed tomography (CT) scan were included. Patients with shoulder fractures were excluded. The resulting scans were split into two groups: patients younger than 25 (group 1) and older than 60 years (group 2). These groups were divided into four subgroups according to gender. Shoulder scans with advanced osteoarthritis were then removed. In order to maintain equal group size, redundant patients were randomly removed. RESULTS: A total of 210 measurements from 106 patients were included. The humeral head diameter (group 1: 41.6 ± 3.7 mm, group 2: 44.5 ± 3.7 mm, p < 0.001) and glenoid surface (group 1: 627.0 ± 110.8 mm(2), group 2: 763.9 ± 148.5 mm(2), p < 0.001) showed higher values in the group of older patients. Older patients also had a higher glenoid inclination (group 1: 50.9 ± 6.9°, group 2: 55.7 ± 8.8°, p < 0.001) as well as an increased glenoid to head ratio (group 1: 0.61 ± 0.04, group 2: 0.64 ± 0.05, p < 0.001). CONCLUSIONS: Increased sizes of humeral head and glenoid surface are present in older patients without signs of osteoarthritis. Moreover, in patients with increased age more glenoid inclination as well as an increased glenoid to head ratio was revealed. These age-dependent anatomical parameters should be considered during planning of operative procedures of the shoulder joint.

Mid-term results of a less-invasive locking plate fixation method for proximal humeral fractures: a prospective observational study.

BACKGROUND: The optimal treatment for proximal humeral fractures remains under debate. In this article, we report the mid-term results of patients who underwent the less-invasive implantation of a polyaxial locking plate for displaced proximal humeral fractures. METHODS: This study included patients who were treated with a polyaxial locking plate via an anterolateral deltoid split approach from May 2008 to December 2011. We evaluated outcome parameters after a minimum follow-up period of 2.5 years (median 4.5 years, follow-up rate 62 %) including the age- and gender-dependent Constant score, the activities of daily living score, and the visual analog scale for both pain and subjective shoulder function. RESULTS: Of the 140 patients who underwent surgery, 114 were included in the follow-up and 71 completed the questionnaire. Fifteen patients (21 %) exhibited 2-fragment fractures, and 56 patients (79 %) exhibited 3- and 4-part fractures. The Constant score improved significantly (4.5 years: 70 ± 21, p < 0.001) between the first two follow-ups (6 weeks: 35 ± 14, 6 months: 56 ± 18, p < 0.001), and also between 6 months and 4.5 years post-surgery. At the final follow-up, the activities of daily living score had not reached pre-fracture levels (before trauma: 27 ± 5, 4.5 years: 20 ± 8, p < 0.001). A multivariate analysis showed that age has a more significant influence on the final outcome than fracture morphology or gender. CONCLUSION: Although the less-invasive surgical procedure is a feasible treatment option in proximal humeral fractures with acceptable complications and considerable improvement during the first six months, a lengthy recovery time is required. The majority of our patients did not become pain-free or reach pre-fracture activity levels.

Fixation of the greater tuberosity in proximal humeral fractures: FiberWire® or wire cerclage?

Proximal humeral fractures remain a surgical challenge, and scientific discussions are commonly focused on their ideal treatment. One possible treatment involves the use of an angle stable plate osteosynthesis. However, which material can most feasibly be used to attach the greater tuberosity to the implant remains unknown. In two prospective, non-randomized trials, we compared the results of a FiberWire® and a wire cerclage. A total of 104 patients with 3- and 4-part fractures were included in this examination. In 25 cases, the greater tuberosity was fixated with a FiberWire®, size 2, while 79 cases received a wire cerclage. Plate osteosynthesis was constantly performed via the anterolateral delta-split approach using the NCB®-PH-plate by Zimmer®. The patients were followed clinically at discharge, 6 weeks and 6 months postoperatively and were examined for relevant complications. Age and gender were equally distributed in both groups. Concerning the follow-up after 6 weeks, a significant benefit concerning shoulder function was observed in the FiberWire®-group (wire cerclage: 39.20±11.85, 95% CI 32.37-44.56, FiberWire®: 45.84±16.80, 95% CI 28.34-61.56: p=0.049). After 6 months, the difference between the groups was not significant (wire cerclage: 58.13±18.73, 95% CI 50.25-72.40, FiberWire®: 68.85±23.10, 95% CI 46.83-99.53: p=0.06).