Two-Stage Exchange Arthroplasty for Periprosthetic Shoulder Infection Is Associated with High Rate of Failure to Reimplant and Mortality.

BACKGROUND: Patients with a periprosthetic joint infection (PJI) of the shoulder, who fail to undergo reimplantation in an attempted two-stage exchange seem to be neglected in the current literature. The aim of this study was to assess the clinical course of patients after the first stage in the process of an attempted two-stage exchange for shoulder PJI. METHODS: After a retrospective review of our institutional database between 2008 and 2018, 49 patients, who were treated with an intended two-stage exchange for shoulder PJI, were identified. Patients' demographics, laboratory and health status parameters, along with records of clinical outcome were collected. The primary outcome measurements analyzed were infection eradication, successful reimplantation, and patient survival. RESULTS: Reimplantation was completed in only 35 (71%) of 49 cases and eradication of infection was achieved in 85.7% of patients with successful reimplantation after a mean follow-up duration of 5.1 years (1.1 to 10.2 years). Reasons for failure to reimplant were premature death in 36%, high general morbidity in 29%, satisfaction with the current status in 21%, or severe infection with poor bone and soft tissues in 14% of the patients. Of the 14 cases without reimplantation, eradication rate of infection was 57% after a mean follow-up of 5 years (2.6 to 11 years). The overall mortality rate of the entire cohort was 25% at the latest follow-up and 10% within ninety days after implant removal. Patients who deceased or did not undergo reimplantation during the follow-up were significantly older and had a significantly higher Charlson comorbidity index (CCI). CONCLUSIONS: While the two-stage exchange arthroplasty can lead to high rates of infection eradication, a considerable subset of patients never undergoes the second stage for a variety of reasons. Shoulder PJI and its treatment are associated with a high risk of mortality, especially in patients with older age and higher CCI.

Middle trapezius transfer for treatment of irreparable supraspinatus tendon tears- anatomical feasibility study.

PURPOSE: The purpose of this study was to investigate the anatomical feasibility of a middle trapezius transfer below the acromion for treatment of irreparable supraspinatus tendon tears. METHODS: This study involved 20 human cadaveric shoulders in 10 full-body specimens. One shoulder in each specimen was dissected and assessed for muscle and tendon extent, force vectors, and distance to the neurovascular structures. The opposite shoulder was used to evaluate the surgical feasibility of the middle trapezius transfer via limited skin incisions along with an assessment of range of motion and risk of neurovascular injury following transfer. RESULTS: The harvested acromial insertion of the middle trapezius tendon showed an average muscle length of 11.7 ± 3.0 cm, tendon length of 2.7 ± 0.9 cm, footprint length of 4.3 ± 0.7 cm and footprint width of 1.4 ± 0.5 cm. The average angle between the non-transferred middle trapezius transfer and the supraspinatus was 33 ± 10° in the transversal plane and 34 ± 14° in the coronal plane. The mean distance from the acromion to the neurovascular bundle was 6.3 ± 1.3 cm (minimum: 4.0 cm). During surgical simulation there was sufficient excursion of the MTT without limitation of range of motion in a retracted scapular position but not in a protracted position. No injuries to the neurovascular structures were noted. CONCLUSION: Transfer of the acromial portion of the middle trapezius for replacement of an irreparable supraspinatus seems to be feasible in terms of size, vector, excursion, mobility and safety. However, some concern regarding sufficiency of transfer excursion remains as scapula protraction can increase the pathway length of the transfer. LEVEL OF EVIDENCE: Basic Science Study/Anatomical Study.

The ligamentous injury pattern in acute acromioclavicular dislocations and its impact on clinical and radiographic parameters.

BACKGROUND: Acromioclavicular (AC) joint dislocations are classified according to the Rockwood (RW) classification, which is based on radiographic findings. Several authors have suggested magnetic resonance imaging (MRI) for visualization of the capsuloligamentous structures stabilizing the AC joint. The aim of this study was to describe the ligamentous injury pattern in acute AC joint dislocations by MRI and investigate associations with clinical and radiographic parameters. METHODS: This prospective study included 45 consecutive patients (5 women and 40 men; mean age, 33.6 years [range, 19-65 years]) with an acute AC joint separation (RW type I in 5, RW type II in 8, RW type III in 18, and RW type V in 14). All patients underwent physical examination of both shoulders, and clinical scores (Subjective Shoulder Value, Constant score, Taft score, and Acromioclavicular Joint Instability Score) were used to evaluate the AC joint clinically as well as radiographically. Post-traumatic radiography included bilateral anteroposterior stress views and bilateral Alexander views to evaluate vertical instability and dynamic posterior translation. MRI was performed for assessment of the AC and coracoclavicular (CC) ligaments and the delto-trapezoidal fascia. RESULTS: Radiographic and MRI classifications were concordant in 23 of 45 patients (51%), whereas 22 injuries (49%) were misjudged; of these, 6 (13%) were reclassified to a more severe type and 16 (36%), to a less severe type. The integrity of the CC ligaments was found to have a clinical impact on vertical as well as horizontal translation determined by radiographs and on clinical parameters. Among patients with an MRI-confirmed complete disruption of the CC ligaments, 68% showed a radiographic CC difference > 30% and 75% showed complete dynamic posterior translation. Inferior clinical parameters were noted in these patients as compared with patients with intact CC ligaments or partial disruption of the CC ligaments (Constant score of 67 points vs. 49 points [P < .05] and Acromioclavicular Joint Instability Score of 51 points vs. 23 points [P < .05]). The inter-rater and intra-rater reliability for assessment of the ligamentous injury pattern by MRI was fair to substantial (r = 0.37-0.66). CONCLUSION: The integrity of the CC and AC ligaments found on MRI has an impact on clinical and radiographic parameters.

Can an acute high-grade acromioclavicular joint separation be reduced and stabilized without surgery? A surgeon's experience.

INTRODUCTION: While the management of Rockwood type III injuries is still a topic of debate, high-grade Rockwood type V injuries are mostly treated surgically, to anatomically reduce the acromioclavicular (AC) joint and to restore functionality. In this case report, we present a method for non-operative reduction and stabilization of a high-grade AC joint injury. CASE: A 31-year-old male orthopaedic resident sustained a Rockwood type V injury during a snowboarding accident. His AC joint was reduced and stabilized with an AC joint brace for six weeks. The brace provided active clavicle depression and humeral elevation. After removal of the brace the AC joint showed a nearly anatomic reduction. Six-month follow-up weighted X-ray views showed an AC joint which had healed in a Rockwood type II position and the patient returned to full pre-injury function with a satisfying cosmetic appearance. CONCLUSION: Non-operative reduction and stabilization of high-grade AC joint separations seems to be a valuable treatment option. A "closed reduction and external fixation" approach with the aid of a dedicated AC joint brace can reduce the AC joint and keep it in place until ligamentous consolidation occurs, thus improving AC joint stability and cosmetic appearance without surgical intervention.

High rate of unexpected positive cultures in presumed aseptic revision of stiff shoulders after proximal humerus osteosynthesis.

BACKGROUND: The aim of this study was to investigate the prevalence of positive microbiology samples after osteosynthesis of proximal humerus fractures at the time of revision surgery and evaluate clinical characteristics of patients with positive culture results. METHODS: All patients, who underwent revision surgery after locked platting, medullary nailing or screw osteosynthesis of proximal humeral fractures between April 2013 and July 2018 were retrospectively evaluated. Patients with acute postoperative infections, those with apparent clinical signs of infection and those with ≤1 tissue or only sonication sample obtained at the time of implant removal were excluded. Positive culture results of revision surgery and its correlation with postoperative shoulder stiffness was analyzed in patients with an interval of ≥6 months between the index osteosynthesis and revision surgery. RESULTS: Intraoperatively obtained cultures were positive in 31 patients (50%). Cutibacterium acnes was the most commonly isolated microorganism, observed in 21 patients (67.7%), followed by coagulase negative staphylococci in 12 patients (38.7%). There were significantly more stiff patients in the culture positive group compared to the culture-negative group (19/21, 91% vs. 15/26, 58%, p = 0.02). Furthermore, 11 of 12 (91.7%) patients with growth of the same microorganism in at least two samples had a stiff shoulder compared to 23 of 35 (65.7%) patients with only one positive culture or negative culture results (p = 0.14). CONCLUSION: Infection must always be considered as a possibility in the setting of revision surgery after proximal humerus osteosynthesis, especially in patients with postoperative stiffness.

The role of implant sonication in the diagnosis of periprosthetic shoulder infection.

BACKGROUND: The aim of this study was to investigate the validity of implant sonication fluid cultures in the diagnosis of shoulder periprosthetic joint infection (PJI) compared with tissue culture. METHODS: This was a retrospective case-control study analyzing all patients who underwent a revision surgery for any kind of suspected septic or aseptic event due to failed shoulder arthroplasty at our institution between July 2014 and December 2018. The diagnostic validity of implant sonication was analyzed on the basis of the last proposed definition criteria of the International Consensus Meeting and compared with standard tissue cultures. RESULTS: Of the 72 patients, a total of 28 (38.9%) were classified as infected. Of the 28 infected patients, 20 (71.4%) had an identified organism by tissue cultures, and Cutibacterium acnes was the most commonly isolated pathogen. The sensitivities of sonicate fluid (≥50 CFU/mL) and periprosthetic tissue culture for the diagnosis of periprosthetic shoulder infection were 36% and 61% (P = .016), and the specificities were 97.7% and 100% (P > .99), respectively. If no cutoff value was used in sonication culture, the sensitivity increased to 75% whereas the specificity dropped to 82%. Although there was no significant difference in sensitivity between tissue culture and the no-cutoff sonication fluid culture (61% vs. 75%, P = .125), the specificity of tissue culture was significantly higher (100% vs. 82%, P = .01). CONCLUSION: Tissue culture showed a higher sensitivity and specificity than implant sonication in the diagnosis of shoulder PJI and should remain the gold standard for microbiological diagnosis of shoulder PJI.

Characteristics of functional shoulder instability.

BACKGROUND: Pathologic activation pattern of muscles can cause shoulder instability. We propose to call this pathology functional shoulder instability (FSI). The purpose of this prospective study was to provide an in-detail description of the characteristics of FSI. METHODS: In the year 2017, a total of 36 consecutive cases of FSI presenting to our outpatient clinic were prospectively collected. Diagnostic investigation included a pathology-specific questionnaire, standardized clinical scores, clinical examination, psychological evaluation, video and dynamic fluoroscopy documentation of the instability mechanism, as well as magnetic resonance imaging (MRI). In a final reviewing process, the material from all collected cases was evaluated and, according to the observed pattern, different subtypes of FSI were determined and compared. RESULTS: Based on the pathomechanism, positional FSI (78%) was distinguished from nonpositional FSI (22%). Controllable positional FSI was observed in 6% of all cases and noncontrollable positional FSI in 72%, whereas controllable and noncontrollable nonpositional FSI were each detected in 11% of the cases. The different subtypes of FSI showed significant differences in all clinical scores (Western Ontario Shoulder Instability Index: P = .002, Rowe Score: P = .001, Subjective Shoulder Value: P = .001) and regarding functional impairment (shoulder stability: P < .001, daily activities: P = .001, sports activities: P < .001). Seventy-eight percent had posterior, 17% anterior, and 6% multidirectional instability. Although several patients showed constitutional glenoid shape alterations or soft tissue hyperlaxity, only few patients with acquired minor structural defects were observed. CONCLUSION: FSI can be classified into 4 subtypes based on pathomechanism and volitional control. Depending on the subtype, patients show different degrees of functional impairment. The majority of patients suffer from unidirectional posterior FSI.

Factors Predicting the Outcome After Arthroscopically Assisted Stabilization of Acute High-Grade Acromioclavicular Joint Dislocations.

BACKGROUND: Factors influencing the outcome after arthroscopically assisted stabilization of acute high-grade acromioclavicular (AC) joint dislocations remain poorly investigated. PURPOSE: To identify determinants of the radiological outcome and investigate associations between radiological and clinical outcome parameters. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The authors performed a retrospective analysis of patients who underwent arthroscopically assisted stabilization for acute high-grade AC joint dislocations. The following potential determinants of the radiological outcome were examined using univariable and multivariable regression analyses: timing of surgery, initial AC joint reduction, isolated coracoclavicular (CC) versus combined CC and AC stabilization, ossification of the CC ligaments, age, and overweight status. In addition, associations between radiological (ie, CC difference, dynamic posterior translation [DPT]) and clinical outcome parameters (Subjective Shoulder Value, Taft score [TS] subjective subcategory, and Acromioclavicular Joint Instability Score [ACJI] pain subitem) were evaluated using univariable analysis. RESULTS: One hundred four patients with a mean (±SD) age of 38.1 ± 11.5 years were included in this study. The mean postoperative follow-up was 2.2 ± 0.9 years. Compared with patients with an overreduced AC joint after surgery, the CC difference was 4.3 mm (95% CI, 1.3-7.3; P = .006) higher in patients with incomplete reduction. Patients with anatomic reduction were 3.1 times (95% CI, 1.2-7.9; P = .017) more likely to develop DPT than those with an overreduced AC joint. An incompletely reduced AC joint was 5.3 times (95% CI, 2.1-13.4; P < .001) more likely to develop DPT versus an overreduced AC joint. Patients who underwent isolated CC stabilization were 4.8 times (95% CI, 1.1-21.0; P = .039) more likely to develop complete DPT than patients with additional AC stabilization. Significantly higher CC difference values were noted for patients who reported pain on the subjective TS (P = .025). Pain was encountered more commonly in patients with DPT (PTS = .049; PACJI = .038). CONCLUSION: Clinicians should consider overreduction of the AC joint because it may lead to favorable radiological results. Because of its association with superior radiographic outcomes, consideration should also be given to the use of additional AC cerclage.

Diagnostic Arthroscopy for Detection of Periprosthetic Infection in Painful Shoulder Arthroplasty.

PURPOSE: To analyze the utility of arthroscopic biopsies for detection of periprosthetic infection in painful shoulder arthroplasty without objective signs of infection. METHODS: A retrospective analysis of all patients who underwent a diagnostic arthroscopy for painful shoulder arthroplasty from June 2012 through July 2018 was performed. Patients with a subsequent revision shoulder arthroplasty after diagnostic arthroscopy were included. Arthroscopic tissue culture results were compared with the culture results of intraoperative tissue samples obtained at the time of open revision surgery. A minimum of 3 tissue samples from synovia and bone-prosthesis interface with signs of synovitis or abnormal appearance was routinely collected. Cases with 2 or more positive cultures for the same microorganism obtained at open revision surgery were considered as true presence of infection. The study protocol was reviewed and approved by the institutional ethics committee. RESULTS: Twenty-three cases in 22 patients were included in this study. Five of these 23 cases were classified as true infection based on the samples obtained during open revision surgery, and 16 cases had a positive culture in diagnostic arthroscopy. Cutibacterium acnes was isolated in each case. Classifying any microbiologic growth in the arthroscopic biopsies as positive resulted in a sensitivity and negative predictive value of 100%, specificity of 39%, and positive predictive value of 31.3% for the detection of a periprosthetic shoulder infection (PPSI). If at least 2 positive samples with the same microbiologic growth in the arthroscopic biopsies were considered as positive, sensitivity and negative predictive value dropped to 80% and 94.4%, respectively, but the specificity and positive predictive value increased to 94.4% and 80%, respectively. CONCLUSIONS: Diagnostic arthroscopy is a useful diagnostic tool in patients with suspicion but no clear evidence of PPSI. Arthroscopically obtained tissue biopsies for culture offer a high sensitivity and specificity in the diagnosis of PPSI if at least 2 cultures positive for the same microorganism are considered as infection. LEVEL OF EVIDENCE: Level III.

Primary versus revision arthroscopically-assisted acromio- and coracoclavicular stabilization of chronic AC-joint instability.

BACKGROUND: A gracilis tendon autograft with TightRope-augmentation can be used for arthroscopically-assisted acromioclavicular (AC)- and coracoclavicular (CC-)stabilization of chronic bidirectional AC-joint instability after failed primary treatment. The impact of failed initial treatment on postoperative outcome is unclear. Hence, the purpose of this study was to evaluate it. METHODS: Twenty-seven of 38 patients suffering from chronic AC-joint instability after either failed conservative (group 1) or surgical treatment (group 2) treated in the above-mentioned technique were finally included in this study. The Subjective Shoulder Value, the Constant Score, the Taft Score and the Acromioclavicular Joint Instability Score were used for clinical evaluation. Bilateral anteroposterior stress radiographs and bilateral Alexander views were obtained for radiological evaluation. RESULTS: 14 patients of group 1 [3f/11m; median age 47.6 (range 20.9-57.4) years] could be evaluated after a median follow-up of 24.3 (range 20-31.2) months and 13 patients of group 2 [6f/7m; median age 44.9 (range 24.9-61.0) years] were available after a median follow-up of 28.8 (range 20-33) months. Comparison of clinical score results revealed no significant differences between both groups. The median CC-difference showed no significant difference between the groups [group 1 0.8 (0-10.5) mm, group 2 0.9 (0-4.3) mm]. CONCLUSION: AC- and CC-stabilization of chronic bidirectional AC-joint instability using a gracilis tendon autograft with TightRope-augmentation can be recommended after failed conservative and surgical treatment. STUDY DESIGN: Retrospective cohort study; Level of evidence III.

Arthroscopic Reconstruction of Multifragmented Anteroinferior Glenoid Rim Fractures.

BACKGROUND: The optimal treatment of anteroinferior glenoid rim fractures remains a matter of debate. Surgical repair aims to prevent persistent instability and osteoarthritic changes of the glenohumeral joint1-3 and is recommended in patients with a subluxated humeral head and substantial displacement of the fracture fragment(s)3-5. Arthroscopic reconstruction with suture anchors was described by Sugaya et al. for large solitary glenoid rim fractures using an indirect reduction and fixation via labral repair6. We present the arthroscopic reconstruction of a multifragmented anteroinferior glenoid rim fracture using a modified knotless anchor technique and bioabsorbable pins. The additional fixation and compression may improve reduction and consolidation of the fracture. DESCRIPTION: The patient is placed in the lateral decubitus position with the affected arm fixed in a traction device. A standard posterior, an anterosuperior (suprabicipital), and a deep anteroinferior portal are required for this minimally invasive technique. A posterolateral portal may be required additionally. First, a diagnostic arthroscopy is performed to identify possible concomitant lesions. Labral repair enables an indirect reduction of the attached fracture fragments and is achieved by the aid of knotless suture anchors. Temporary reduction using Kirschner wires can be applied. Bioabsorbable pins can be used for additional ultimate fixation and compression of the fracture fragments. ALTERNATIVES: A variety of surgical techniques for the reconstruction of glenoid rim fractures have been described in the literature, including open or arthroscopic screw osteosynthesis using either metallic or bioabsorbable screws3,6-10. Screw osteosynthesis, however, is not a feasible option for fractures with multiple small fragments3. Isolated suture anchor reconstruction represents another alternative6. Good clinical results and a high subjective satisfaction rate, however, can also be achieved by nonoperative treatment, depending on the patient and fracture characteristics3,10-12. RATIONALE: This minimally invasive technique enables an almost anatomical reconstruction of the glenoid rim with a minor risk of hardware impingement compared with screw osteosynthesis.

Acromioclavicular joint cyst formation in a patient with rotator cuff-tear arthropathy: a rare cause of shoulder discomfort.

We report a case of a 77-year-old man who presented to our shoulder department with a soft tissue mass on his right acromioclavicular (AC) joint. Previously attempted puncture aspiration had revealed serous fluid retention which recurred after each of several drainage attempts. Conventional radiography and MRI of the affected shoulder joint demonstrated a progressed cuff-tear arthropathy with an irreparable tear of the supraspinatus tendon, static superior migration of the humeral head, opening of the AC joint capsule and a superior joint-fluid 'eruption' and accumulation called 'Geyser sign'. Given that the patient's cuff-tear arthropathy was very well compensated, arthroscopic rotator cuff debridement and open cyst excision were performed. Closure of the superior aspect of the AC joint capsule was performed by the aid of a collagen matrix with additional closure of the deltotrapezial fascia. One year postoperatively, no cyst recurrence was noted.

Combined arthroscopically assisted coraco- and acromioclavicular stabilization of acute high-grade acromioclavicular joint separations.

PURPOSE AND HYPOTHESIS: Due to high rate of persisting dynamic posterior translation (DPT) following isolated coracoclavicular double-button technique for reconstruction of the acromioclavicular (AC) joint reported in the literature, an additional acromioclavicular cerclage was added to the procedure. The aim of this study was to evaluate the clinical and radiological results of patients with high-grade AC-joint instability treated with a double TightRope technique with an additional percutaneous acromioclavicular cerclage. METHODS: Fifty-nine patients (6 f/53 m; median age 38.3 (range 21.5-63.4 years) who sustained an acute high-grade AC-joint dislocation (Rockwood type V) were treated using the above-mentioned technique. At the final follow-up, the constant score (CS), the subjective shoulder value (SSV), the Taft score (TF) and the acromioclavicular joint instability score (ACJI) as well as bilateral anteroposterior stress views with 10 kg of axial load and bilateral modified Alexander views were obtained. RESULTS: At a median follow-up of 26.4 (range 20.3-61.0) months, 34 patients scored a median of 90 (33-100) points in the CS, 90 (25-100) % in the SSV, 11 (4-12) points in the TF and 87 (43-100) points in the ACJI. The coracoclavicular (CC) distance was 12.1 (6.5-19.8) mm and the CC difference 2.0 (0.0-11.0) mm. Two patients (5.8%) showed a complete DPT of the AC joint, and fourteen patients (41.1%) displayed a partial DPT. The overall revision rate was 11.7%. Two patients presented implant irritation, one patient a recurrent instability, and one patient suffered from a local infection. CONCLUSION: The arthroscopically assisted and image-intensifier-controlled double TightRope technique with an additional percutaneous acromioclavicular cerclage leads to good and excellent clinical results after a follow-up of 2 years. The incidence of persisting dynamic horizontal translation is lower compared to isolated coracoclavicular stabilization. Thus, we recommend using the double TightRope implant with an additional acromioclavicular cerclage. LEVEL OF EVIDENCE: IV.

Elbow flexion and forearm supination strength in a healthy population.

BACKGROUND AND HYPOTHESIS: Despite the lack of representative data of a healthy population, many clinical trials concerning the measurement of postoperative elbow flexion or forearm supination strength use the contralateral side as a control. We hypothesized that there are no differences in elbow flexion and supination strength between the dominant and nondominant sides in healthy volunteers. METHODS: The study was performed on a cross-sectional cohort of healthy subjects without any prior injuries or surgical interventions of the upper extremities. Isometric elbow flexion strength and supination strength were measured on both the dominant and nondominant sides. The results were analyzed for the entire group and subanalyzed for female vs. male, for different age groups, and according to handedness and regular practice of overhead sports. RESULTS: A total of 150 subjects (75 female and 75 male subjects; mean age, 44 ± 15 years [range, 18-72 years]) were included in this study. Within the entire collective, no significant differences concerning the elbow flexion strength between the dominant and nondominant sides could be detected, whereas the supination strength was 7% higher on the dominant side (P = .010). Women, right-hand-dominant subjects, and subjects who do not regularly practice overhead sports have a significant 8% higher supination strength on the dominant side compared with the nondominant side (P < .05). Left-hand-dominant subjects have an 8% higher elbow flexion strength on the nondominant right side (P < .05). CONCLUSION: Elbow flexion strength and forearm supination strength differ between the dominant and nondominant sides. The contralateral upper extremity cannot be used as a matched control without some adjustments.