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.

[MCL tear with intra-articular dislocation]. / MCL-Ruptur mit intraartikulärer Dislokation.

A 48-year-old male patient presented with inner skin retraction after a sports accident involving the knee. In a multi-ligament injury it must be assumed that knee dislocation has occurred. Inner skin retraction after knee distortion can result from an intra-articular dislocation of the ruptured medial collateral ligament. Prompt reduction and exclusion of concomitant neurovascular injuries is thus obligatory. After surgical reconstruction of the medial collateral ligament, instability was no longer apparent 3 months postoperatively.

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.

The lack of retropatellar resurfacing at index surgery is significantly associated with failure in patients following patellofemoral inlay arthroplasty: a multi-center study of more than 260 patients.

PURPOSE: To evaluate the clinical outcomes of patients with a minimum 2-year follow-up following contemporary patellofemoral inlay arthroplasty (PFIA) and to identify potential risk factors for failure in a multi-center study. METHODS: All patients who underwent implantation of PFIA between 09/2009 and 11/2016 at 11 specialized orthopedic referral centers were enrolled in the study and were evaluated retrospectively at a minimum 2-year follow-up. Clinical outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Tegner Scale, the visual analogue scale (VAS) for pain, and subjective patient satisfaction. Pre- and perioperative risk factors were compared among failures and non-failures to determine potential risk factors. RESULTS: A total of 263 patients (85% follow-up rate) could be enrolled. The mean age at the time of index surgery was 49 ± 12 years with a mean postoperative follow-up of 45 ± 18 months. The overall failure rate was 11% (28 patients), of which 18% (5 patients) were patients with patella resurfacing at index surgery and 82% (23 patients) were patients without initial patella resurfacing. At final follow-up, 93% of the patients who did not fail were satisfied with the procedure with a mean transformed WOMAC Score of 84.5 ± 14.5 points, a mean KOOS Score of 73.3 ± 17.1 points, a mean Tegner Score of 3.4 ± 1.4 points and a mean VAS pain of 2.4 ± 2.0 points. An increased BMI was significantly correlated with a worse postoperative outcome. Concomitant procedures addressing patellofemoral instability or malalignment, the lack of patellofemoral resurfacing at the index surgery and a high BMI were significantly correlated with failure in our patient cohort. CONCLUSION: Patellofemoral inlay arthroplasty shows high patient satisfaction with good functional outcomes at short-term follow-up and thus can be considered a viable treatment option in young patients suffering from isolated patellofemoral arthritis. Patellar resurfacing at index surgery is recommended to decrease the risk of failure. LEVEL OF EVIDENCE: Retrospective case series, Level IV.

Elective shoulder surgery during the coronavirus disease 2019 pandemic in Germany: the patients' perspective.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has impeded the treatment of elective shoulder patients all over the world. Owing to the constraints in personnel and operation theater capacities, many patients who should undergo planned surgeries could not receive medical care. In our study, we examined the status quo of elective shoulder arthroscopy during the pandemic in Germany. METHODS: Using a nonprofit database, 40 shoulder units that performed the most arthroscopic rotator cuff repairs in Germany in 2018 were identified. Following a standardized protocol, the web pages of these units were screened, and their strategy for elective procedures during the COVID-19 pandemic was analyzed. Special emphasis was put on the use of new digital technologies. RESULTS: At the time of the study, no unit had stopped scheduling appointments for elective shoulder patients because of the pandemic. Almost all units (97.5%) offered explicit information about COVID-19 and their strategies toward it. The possibilities of visiting patients in shoulder units varied owing to local restrictions. Two units (5%) offered digital consultations. CONCLUSION: At the time of the study, elective shoulder procedures could be planned and carried out at the largest centers in Germany. Local restrictions had a great influence on the organization of the procedure and hospital stay during the COVID-19 pandemic. Digital consultations were not available in every unit.

Planning Results for High Tibial Osteotomies in Degenerative Varus Osteoarthritis Using Standing and Supine Whole Leg Radiographs.

OBJECTIVE: In this study, we hypothesized that standing and supine X-rays lead to different preoperative planning results. METHODS: The present study included 168 pictures from 81 patients who were treated surgically with high tibial osteotomy (HTO) for varus deformity between January 2017 and February 2018. Each patient underwent whole leg X-ray examinations in both standing and supine position. On both images, the following parameters were measured: degree of axis deviation (DAD), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), width of medial (MJS) and lateral joint space (LJS), and the correction angle (CA). The results were correlated with the patients' age and body mass index (BMI). To analyze intra-observer reliability, the same researcher, blinded to the previous measurements, remeasured all X-rays from 10 patients 8 weeks after the initial measurements were carried out. RESULTS: While mLDFA (P = 0.075), mMPTA (P = 0.435), and MJS (P = 0.119) did not show any differences between the two modalities, LJS (P = 0.016) and DAD (P < 0.001) differed significantly, leading to different correction angles (P < 0.001). The mean difference of the CA was 1.7° ± 2.2° (range, -2.6° to-15.4°). In 14 legs (17%), the standing X-ray led to a correction angle that was at least 3° larger than the calculation revealed in the supine X-ray; in 4 legs (5%), it was at least 5° larger. Increased BMI (r = 0.191, P = 0.088) and older age (r = 0.057 , P = 0.605) did not show relevant correlation with DAD differences. However, more severe varus malalignment in the supine radiograph did correlate moderately with differences of correction angles between supine and weight-bearing radiographs (r = 0.414, P < 0.001). The analysis of the intra-rater reliability revealed mediocre to excellent intercorrelation coefficients between the measurements of the observer. CONCLUSION: The use of supine and standing X-ray images leads to different planning results when performing high tibial osteotomies for varus gonarthrosis. To avoid potential overcorrection, surgeons might consider increased lateral joint spaces on standing radiographs in osteoarthritic knees with varus deviation.

Effects of focal metallic implants on opposing cartilage - an in-vitro study with an abrasion test machine.

BACKGROUND: For focal cartilage defects, biological repair might be ineffective in patients over 45 years. A focal metallic implant (FMI) (Hemi-CAP Arthrosurface Inc., Franklin, MA, USA) was designed to reduce symptoms. The aim of this study was to evaluate the effects of a FMI on the opposing tibial cartilage in a biomechanical set-up. It is hypothesized that a FMI would not damage the opposing cartilage under physiological loading conditions. METHODS: An abrasion machine was used to test the effects of cyclic loading on osteochondral plugs. The machine applied a compressive load of 33 N and sheared the samples 10 mm in the anteroposterior direction by 1 Hz. Tibial osteochondral plugs from porcine knees were placed in opposition to a FMI and cycled for 1 or 6 h. After testing each plug was fixed, stained and evaluated for cartilage damage. RESULTS: After 1 h of loading (n = 6), none of the osteochondral plugs showed histologic signs of degradation. After 6 h of loading (n = 6) three samples had histologic signs of injury in the tangential zone (grade 1) and one had signs of injury in the transitional and deep zones (grade 2). Exploration for 6 h resulted in significant more cartilage damage compared to the shorter exploration time (p = 0.06). However, no significant difference between saline and hyaluronic acid was evident (p = 0.55). CONCLUSION: Under physiologic loading conditions, contact with a FMI leads to cartilage damage in the opposing articular cartilage in six hours. In clinical practice, a thorough analysis of pre-existing defects on the opposing cartilage is recommended when FMI is considered.

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.

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.

The Diagnosis and Treatment of Acute Dislocation of the Acromioclavicular Joint.

BACKGROUND: The acromioclavicular joint (ACJ) is one of the more common sites of shoulder girdle injury, accounting for 4-12% of all such injuries, with an incidence of 3-4 cases per 100 000 persons per year in the general population. Current topics of debate include the proper standard diagnostic evaluation, the indications for surgery, and the best operative method. METHODS: This review is based on publications retrieved by a selective literature search. RESULTS: Mechanical trauma of the ACG can tear the ligamentous apparatus that holds the acromion, clavicle, and coracoid process together. Different interventions are indicated depending on the nature of the injury. In recent years, the horizontal component of the instability has received more attention, in addition to its vertical component. Persistent instability can lead to chronic, painful limitation of shoulder function, particularly with respect to working above the head. Surgical stabilization is therefore recommended for high-grade instability of Rockwood types IV and V. Modern reconstruction techniques enable selective vertical and horizontal treatment of the instability and have been found superior to traditional methods, particularly in young athletes. Arthroscopic techniques are advantageous because they are less invasive, do not require removal of implanted material, and afford the opportunity to diagnose any accompanying lesions definitively and to treat them if necessary. Surgery for acute injuries should be performed within three weeks of the trauma. For chronic injuries, additional tendon augmentation is now considered standard treatment. CONCLUSION: High-grade ACJ instability is a complex and significant injury of the shoulder girdle that can cause persistent pain and functional impairment. The state of the evidence regarding its optimal treatment is weak. Large-scale, prospective, randomized comparative studies are needed in order to define a clear standard of treatment.

Influence of Sutures on Cartilage Integrity: Do Meniscus Sutures Harm Cartilage? An Experimental Animal Study.

PURPOSE: To evaluate whether different suture materials in meniscal repair may harm cartilage. METHODS: A preloaded linear friction testing setup including porcine knees with porcine cartilage, porcine meniscus, and different suture materials (braided nonabsorbable, absorbable monofilament) was used. Five groups with different tribological pairs were tested: cartilage on meniscus (control), cartilage on cartilage (control No. 2), and cartilage on different meniscus sutures (3 groups). Cartilage integrity was analyzed macroscopically by the India ink method and histologically using Giemsa-eosin-stained undecalcified methyl methacrylate sections. Cartilage lesions were classified by using a quantitative scoring system. RESULTS: The control groups did not show cartilage damage, either macroscopically or histologically. Loading cartilage with sutured menisci led to significant damage of the superficial radial and transitional zones with braided nonabsorbable (P = .03) and absorbable monofilament (P = .02) sutures at final examination. Menisci sutured with braided nonabsorbable material resulted in deeper damage to the cartilage. However, there were no significant differences between the suture materials. Sutures oriented perpendicular to surface motion led to a larger defect than parallel-oriented sutures. CONCLUSIONS: Braided nonabsorbable and absorbable monofilament suture materials cause significant damage to cartilage during long-term cyclic loading in vitro. The extent of damage depends on suture orientation. CLINICAL RELEVANCE: This study provides data on the extent to which different suture materials in meniscus repair may harm cartilage.

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.

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.

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.

Surgical treatment of patellar instability: clinical and radiological outcome after medial patellofemoral ligament reconstruction and tibial tuberosity medialisation.

INTRODUCTION: The aim of this retrospective study was to analyse clinical and radiological outcome after medial patellofemoral ligament reconstruction (MPFLR) and tibial tuberosity medialisation (TTM) in patients with recurrent patellar instability. MATERIALS AND METHODS: Thirty-five patients were included between 2008 and 2012. According to defined criteria such as tibial tuberosity-trochlear groove (TTTG) distance, hyperpression on the lateral patella facet and lateral retropatellar cartilage damage either MPFLR (group A) or TTM (group B) was performed: 18 patients underwent TTM, the other 17 patients underwent MPFLR. At a mean of 25.4 ± 9.7 (group A) and 35.2 ± 17.6 months (group B) patients were clinically and radiologically reviewed. Validated knee scores such as Kujala, Lysholm and Tegner score were evaluated. RESULTS: In both groups one patient reported of a non-traumatic patellar redislocation. Patients who underwent MPFLR (group A) had less pain postoperatively during activity according to the Visual Analogue Scale (group A: 2.0 ± 2.1 points, group B: 3.9 ± 2.3 points). Retropatellar cartilage damage increased in group B from grade 1 (range: 1-3) preoperatively to grade 2 (range 1-3) postoperatively (p > 0.05). All other clinically evaluated items, as well as the applied knee scoring systems, indicated no significant difference (p > 0.05) and displayed good to excellent results. CONCLUSIONS: MPFLR and TTM leed to good clinical results despite its own indications. For this reason-in selected cases-TTM may still be a suitable procedure for surgical treatment of patellar instability. However, patients treated by TTM (group B) revealed an increased retropatellar cartilage damage as well as significantly more pain during activity.

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.

Additional calcar support using a blade device reduces secondary varus displacement following reconstruction of the proximal humerus: a prospective study.

BACKGROUND: Locking plate fixation of displaced fractures of the proximal humerus is still accompanied by a distinct complication rate, especially in case of osteoporotic bone, short-segment fracture length and comminution of the medial calcar. Secondary loss of reduction leading to varus deformity and screw cutout most frequently lead to surgical revision. The aim of the present study was to evaluate the clinical and radiological outcome of a recently developed polyaxial locking plate that allows for the additional placement of a helical blade device, aiming for support of the medial calcar. METHODS: In this prospective study, 17 patients with a mean age of 63.0 ± 16.0 years suffering from displaced fractures of the proximal humerus (Neer type two-, three- and four-part) were enrolled. All patients were surgically treated using a polyaxial locking plate with additional blade device (group PAB, n = 12) or without blade device (group PA, n = 5). Functional outcome was recorded using the Munich Shoulder Questionnaire allowing for qualitative self-assessment of the Shoulder Pain and Disability Index (SPADI), the Disability of the Arm, Shoulder and Hand (DASH score) and the Constant Score. Radiological outcome was assessed by analyzing standardized true anterior-posterior and outlet-view radiographs with respect to radiographic evidence of secondary varus displacement, cutout of screws and hardware failure. Results were compared to an age-, gender- and fracture type-matched collective treated by monoaxial locking plate fixation (group MA, n = 15). RESULTS: The mean follow-up was 12.4 ± 2.9 months after surgery. There were no statistical significant differences in clinical outcome in all three groups. Group MA and group PA revealed significant secondary varus displacement in comparison to group PAB at the final follow-up compared to postoperative analysis (p < 0.001). The distance between the blade and the articular surface showed no significant increase in group PAB at the final follow-up compared to postoperative analysis. Not-implant-related complications were seen in one and implant-related complications were seen in two patients in group PAB. CONCLUSIONS: Polyaxial locking plate fixation with a blade device to restore medial cortical support reduces the risk of secondary varus displacement even in proximal humeral fractures of the elderly in comparison to monoaxial and polyaxial locking plate fixation without blade insertion.

Arthroscopic Removal of a Polyethylene Glenoid Component in Total Shoulder Arthroplasty.

We present a technique for arthroscopic glenoid removal in a case of glenoid loosening after total shoulder arthroplasty (TSA). The presented technique is technically feasible and may be useful if 1-stage surgery with glenoid reimplantation is not indicated. To exclude low-grade infection, the presented technique allows for an intraoperative infection workup such as intraoperative cultures. However, glenoid loosening in TSA is a well-known problem and has been described before. The advantages of the presented technique include minimally invasive surgery, decreased pain, preservation of the subscapularis tendon, and assurance of exclusion of low-grade infection before reimplantation of a new glenoid implant. In this case a 73-year-old patient was treated with a TSA for severe osteoarthritis of the right shoulder in April 2014. Because of persistent anterior shoulder pain postoperatively, radiographic evaluation was performed and showed signs of glenoid loosening 6 months after surgery without any clinical signs of infection. To exclude low-grade infection, arthroscopy of the right shoulder was performed. Arthroscopy showed a totally loosened glenoid component leading to arthroscopic glenoid removal by use of a special forceps.

Value of additional acromioclavicular cerclage for horizontal stability in complete acromioclavicular separation: a biomechanical study.

PURPOSE: To evaluate whether isolated anatomical coracoclavicular (CC) ligament reconstruction with two suture-button devices provides equal horizontal acromioclavicular joint (ACJ) stability compared to additional ACJ suture tape cerclage. METHODS: A servohydraulic testing machine was used to assess horizontal ACJ translation in 12 fresh-frozen human shoulders during 5,000 cycles of dynamic anteroposterior directed loading (70 N). Horizontal ACJ stability was assessed for native specimen (n = 6) and compared to specimen with dissected AC ligaments but intact CC ligaments (n = 6). After complete AC/CC dissection, an anatomical CC reconstruction was performed with two suture-button devices (n = 6) and compared to the additional ACJ suture tape cerclage (n = 6). RESULTS: Native specimen showed an mean horizontal amplitude of 10.8 mm [standard deviation (SD) 3.29]. After 5,000 cycles of horizontal loading (70 N), mean amplitude increased by 1.5 mm (SD 0.75, p = 0.005). Specimen with dissected AC ligaments started at an mean amplitude of 14.1 mm (SD 4.11), which was increased by 0.9 mm (SD 0.56, n.s.) after loading. Initially, amplitude of specimen with anatomical CC reconstruction was 13.2 mm (SD 2.75), which increased by 2.9 mm (SD 1.45, p = 0.001) after loading. The specimen with additional AC cerclage initially showed an amplitude of 10.6 mm (SD 2.35). After loading, translation was increased by 3.0 mm (SD 0.97, p = 0.001). There was no failure of any surgical reconstruction in the tests. CONCLUSION: The results of this study suggest that only combined AC and CC reconstruction can adequately re-establish physiological horizontal ACJ stability. Therefore, it is likely that a combined surgical procedure with double suture-button devices and AC suture tape cerclage can adequately re-establish horizontal AC joint stability in case of an acute injury (≥type Rockwood IV and may allow superior clinical outcomes for patients, especially if early functional rehabilitation is intended).

Evidence of an autoregulatory mechanism of regional bone blood flow at hypotension.

BACKGROUND: Blood flow in various organs is determined by an autoregulatory mechanism that guarantees constant organ perfusion over a wide range of arterial blood pressure changes. This physiological principle has been proven for the kidney, brain and intestinal tract, but so far not for bone. This study was carried out to determine whether there is an autoregulatory mechanism of bone or not. METHODS: The fluorescent microsphere reference sample method was used to determine blood flow within the bone and kidneys. Eight anesthetized female New Zealand rabbits received left ventricular injections of fluorescent microspheres over a wide range of arterial pressure levels prior to removal of kidney, femur and tibia. Blood flow values were calculated by measurement of fluorescence intensity in kidney and bone and correlated to fluorescence intensity in the peripheral blood (reference sample). RESULTS: Despite a reduction of mean arterial pressure from 100 to 80 mmHg bone blood flow remained constant. Further reduction of mean arterial pressure results in a linear decrease in bone blood flow. CONCLUSION: The correlation between arterial pressure and organ perfusion in the bone is similar to blood flow within the kidney, indicating the presence of an autoregulated blood flow mechanism within the bone tissue.