Lateral ulnar collateral ligament reconstruction using an autologous triceps tendon graft for subclinical posterolateral rotatory instability in recalcitrant lateral epicondylitis.

PURPOSE: To evaluate midterm outcome of lateral ulnar collateral ligament (LUCL) repair with triceps autograft in patients with PLRI under recalcitrant lateral epicondylitis. METHODS: In total, 25 elbows (23 patients) with recalcitrant epicondylitis longer than 12 months were included into this retrospective study. All patients underwent arthroscopic instability examination. In 18 elbows (16 patients, mean age 47.4 years, range 25-60), PLRI was verified, and an LUCL repair using an autologous triceps tendon graft was performed. Clinical outcome was evaluated before and at least 3 years after surgery using the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form-Elbow Score (ASES-E), Liverpool Elbow Score (LES), Mayo Elbow Performance Index (MEPI), Patient-Rated Elbow Evaluation score (PREE), Subjective Elbow Value (SEV), quick Disabilities of the Arm, Shoulder, and Hand score (qDASH), and the visual analog scale (VAS) for pain. Postoperative satisfaction with the procedure and complications were recorded. RESULTS: Seventeen patients were available at a mean follow-up of 66.4 months (range 48-81). Patient satisfaction postoperatively was reported in 15 elbows as excellent (90%-100%) and 2 as moderate, with 93.1% overall. All scores of the 3 female and 12 male patients significantly increased from pre- to the postoperative follow-up (ASES: 28.3 ± 10.7 to 54.6 ± 12.1, P < .001; MEPI: 49.2 ± 8.3 to 90.5 ± 15.4, P < .001; PREE: 66.1 ± 14.9 to 11.3 ± 23.5, P < .001; qDASH: 63.2 ± 21.1 to 11.5 ± 22.6, P < .001; VAS: 8.75 ± 1.0 to 1.5 ± 2.0, P < .001). All patients suffered from high extension pain preoperatively, which was reported to be relieved after surgery. No recurrent instability or major complication occurred. CONCLUSION: The repair and augmentation of the LUCL with a triceps tendon autograft reached significant improvements; hence, it seems to be a good treatment option for posterolateral elbow rotatory instability with promising midterm results under a low rate of recurrent instability.

Biomechanical properties of a suture anchor system from human allogenic mineralized cortical bone matrix for rotator cuff repair.

BACKGROUND: Suture anchors (SAs) made of human allogenic mineralized cortical bone matrix are among the newest developments in orthopaedic and trauma surgery. Biomechanical properties of an allogenic mineralized suture anchor (AMSA) are not investigated until now. The primary objective was the biomechanical investigation of AMSA and comparing it to a metallic suture anchor (MSA) and a bioabsorbable suture anchor (BSA) placed at the greater tuberosity of the humeral head of cadaver humeri. Additionally, we assessed the biomechanical properties of the SAs with bone microarchitecture parameters. METHODS: First, bone microarchitecture of 12 fresh frozen human cadaver humeri from six donors was analyzed by high-resolution peripheral quantitative computed tomography. In total, 18 AMSAs, 9 MSAs, and 9 BSAs were implanted at a 60° angle. All three SA systems were systematically implanted alternating in three positions within the greater tuberosity (position 1: anterior, position 2: central, position 3: posterior) with a distance of 15 mm to each other. Biomechanical load to failure was measured in a uniaxial direction at 135°. RESULTS: Mean age of all specimens was 53.6 ± 9.1 years. For all bone microarchitecture measurements, linear regression slope estimates were negative which implies decreasing values with increasing age of specimens. Positioning of all three SA systems at the greater tuberosity was equally distributed (p = 0.827). Mean load to failure rates were higher for AMSA compared to MSA and BSA without reaching statistical significance between the groups (p = 0.427). Anchor displacement was comparable for all three SA systems, while there were significant differences regarding failure mode between all three SA systems (p < 0.001). Maximum load to failure was reached in all cases for AMSA, in 44.4% for MSA, and in 55.6% for BSA. Suture tear was observed in 55.6% for MSA and in 22.2% for BSA. Anchor breakage was solely seen for BSA (22.2%). No correlations were observed between bone microarchitecture parameters and load to failure rates of all three suture anchor systems. CONCLUSIONS: The AMSA showed promising biomechanical properties for initial fixation strength for RCR. Since reduced BMD is an important issue for patients with chronic rotator cuff lesions, the AMSA is an interesting alternative to MSA and BSA. Also, the AMSA could improve healing of the enthesis.

Rotator Cuff Delamination Is Associated With Increased Tendon Retraction and Higher Fatty Muscle Infiltration: A Comparative Study on Arthroscopy and Magnetic Resonance Imaging.

PURPOSE: To investigate (1) tendon delamination according to different rotator cuff tear patterns as well as (2) the association of tendon retraction and fatty muscle infiltration with delamination of the rotator cuff. Furthermore, we aimed to establish the accuracy of magnetic resonance imaging for the detection of rotator cuff delamination. METHODS: Magnetic resonance imaging scans of patients who underwent arthroscopic rotator cuff repair from 2013 to 2015 were retrospectively compared to intraoperative findings. Prevalences of tendon delamination, tendon retraction, and fatty muscle infiltration were categorized according to different rotator cuff tear patterns. For comparability of the amount of tendon retraction of delaminated and non-delaminated rotator cuff tears, we introduced the global retraction index, a description individually assessing tendon retraction in magnetic resonance imaging scans of all visible layers. RESULTS: Of 349 shoulders, tendon delamination was observed in 231 patients (66.2%). Of these, rotator cuff delamination was most commonly seen in posterosuperior rotator cuff tears (84.6%). Delaminated rotator cuff tears presented with a significantly higher global retraction index (P < .001) as well as higher fatty muscle infiltration of the supraspinatus (P = .001) and infraspinatus (P = .001). Magnetic resonance imaging had only moderate accuracy (57.3%) to detect rotator cuff delamination, with a positive predictive value of 100% (95% confidence interval [CI] 95.6% to 100.0%) and a negative predictive value of 44.2% (95% CI 38.1% to 50.4%). CONCLUSIONS: Tendon delamination was most commonly observed in posterosuperior rotator cuff tears. Delaminated rotator cuff tears showed a significantly greater tendon retraction as well as a higher amount of fatty muscle infiltration of the supraspinatus and infraspinatus. Magnetic resonance imaging has only moderate accuracy for detection of rotator cuff delamination. LEVEL OF EVIDENCE: III, retrospective cohort study.

Allo- and autografts show comparable outcomes in chronic acromioclavicular joint reconstruction: a systematic review.

PURPOSE: The aim of this review was to compare clinical and radiological outcome of acromio-clavicular joint reconstruction with allografts versus autografts. METHODS: The PubMed, MEDLINE, The Cochrane Library and WEB OF SCIENCE databases were searched in accordance with the PRISMA guidelines until February 2020 using the terms: 'coracoclavicular' OR 'coraco-clavicular' OR 'acromioclavicular' OR 'acromio-clavicular joint', AND 'reconstruction'. All studies reporting on clinical and radiological outcome as well as complications after ACJ reconstruction using allo- and/or autografts were included. RESULTS: A total of 29 articles, including 2 prospective and 27 retrospective studies, involving 622 patients, reconstructed with either allo- (n = 360) or auto-grafts (n = 262), for acromio-clavicular joint instability were identified and included in this review. The majority of studies had low sample sizes (66.7% below n = 20), were retrospective (93.3%), with short-term follow-ups (average 26.2 ± 12.6 months; range 6-186). The study with the largest sample size (n = 128) did not report clinical outcome. A comparison between allo- and auto-graft showed no significant differences regarding age, gender, and follow-up times. Clinical outcome was comparable in both groups, loss of reduction (LOR) and complication rates were higher in the allograft group. Overall a reduction of LOR was shown if additional horizontal stabilization was performed. Also a higher LOR and revision rate was documented in allografts without suture or suture-tape augmentation. The use of more clavicular drill-holes correlated with a higher frequency of fracture. CONCLUSIONS: A systematic review of the available peer-reviewed literature addressing allograft and autograft reconstruction of unstable coracoclavicular ligaments shows that the published studies are generally of low quality with low levels of evidence. The published literature shows no significant difference in clinical outcomes between the use of autografts or allografts in ACJ reconstruction surgery. Surgical techniques utilizing additional horizontal stabilization may contribute to lower rates of LOR. In cases where allograft tissue is used for ACJ reconstruction the use of suture/tape augmentation may reduce LOR rates as well as revision rates. LEVEL OF EVIDENCE: III.

Cutibacterium Acnes (Formerly Propionibacterium Acnes) Contamination of the Surgical Field During Shoulder Arthroscopy.

PURPOSE: To evaluate the prevalence of Cutibacterium acnes in the shoulder region and to analyze changes in C acnes contamination during shoulder arthroscopy, as well as to investigate the influence of sex and type of arthroscopic surgery on those parameters. METHODS: Forty-eight consecutive patients undergoing reconstructive or non-reconstructive shoulder arthroscopy, after hair removal with a medical clipper, routine antibiotic prophylaxis, and skin preparation with an alcohol-based skin disinfectant, were prospectively enrolled in this study. The shoulder was divided into 4 regions of interest (anterior, medial, posterior, and axilla). Skin swabs were taken from each region at 3 time points (preoperatively before and after skin preparation, and at the conclusion of surgery), cultured for 21 days, and analyzed for the prevalence of C acnes. RESULTS: The rate of C acnes-positive skin cultures was significantly increased at the end of surgery compared with preoperatively before (44.3% vs 27.6%, P < .001) and after (44.3% vs 31.3%, P = .001) skin preparation. No reduction in C acnes was observed with preoperative skin preparation (27.6% vs 31.3%, P = .401). At the end of shoulder arthroscopy, 64.6% of patients showed at least 1 culture positive for C acnes. The C acnes prevalence was significantly higher in male patients (48.3%) than female patients (20.1%, P < .001), at all time points (P < .016), and in all regions of interest (P < .001) except the axilla. No differences in the prevalence of C acnes were found between non-reconstructive and reconstructive procedures. CONCLUSIONS: Skin contamination with C acnes around the shoulder increased significantly from before and after skin preparation to the conclusion of surgery in patients undergoing shoulder arthroscopy despite perioperative preventive measures. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

The knotless cinch-bridge technique for delaminated rotator cuff tears leads to a high healing rate and a more favorable short-term clinical outcome than suture-bridge repair.

PURPOSE: To compare functional outcomes and magnetic resonance image (MRI) tendon integrity following either the suture bridge or the knotless cinch-bridge technique used for arthroscopic double-layer rotator cuff repair. METHODS: 37 prospectively enrolled patients (46-76 years), who were treated with arthroscopic double-layer rotator cuff repair (group 1: suture bridge n = 20, group 2: cinch bridge n = 17) were clinically and radiographically assessed before and at an average of 24.0 ± 4.7 months after the procedure. Shoulder function was evaluated by the constant score (CS), range of motion, and various patient-related scores. Repaired tendon integrity was evaluated by MRI. Peri- and postoperative complications were recorded. RESULTS: All functional and patient-related scores significantly improved from pre- to postoperative. Significantly better postoperative CS (P = 0.037), flexion (P < 0.001), and abduction (P = 0.009) were detected after arthroscopic cinch compared to suture-bridge repair. The mean CS improvements from baseline to follow-up were not significantly different between the groups (n.s.). Patient-related scores did not show any statistical significant differences. The MRI healing rate following arthroscopic double-layer repair with the suture- and cinch-bridge technique was 95% and 94%, respectively. Fatty infiltration regarding the supraspinatus and infraspinatus increased in 55% and 35% (group 1) and in 53% and 48% (group 2), respectively. Muscle hypotrophy remained stable in all patients. Overall, 92% of the patients were very satisfied or satisfied with the procedure. No complications were detected. CONCLUSIONS: Arthroscopic knotless double-layer rotator cuff repair with the cinch-bridge technique showed higher CS, forward flexion, and abduction values, as well as similar patient-related short-term outcome and MRI integrity compared to the suture-bridge technique. These results highlight the potential importance of less tendon strangulation for better clinical short-term outcome. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Radiological changes do not influence clinical mid-term outcome in stemless humeral head replacements with hollow screw fixation: a prospective radiological and clinical evaluation.

BACKGROUND: Stemless shoulder arthroplasty is a fairly new concept. Clinical and radiological follow-up is essential to prove implant safety and concept. This prospective single-centre study was performed to evaluate the influence of radiological changes on clinical mid-term outcome following stemless humeral head replacement with hollow screw fixation. METHODS: Short- and mid-term radiological and clinical evaluations were performed in 73 consecutive shoulders treated mainly for idiopathic and posttraumatic osteoarthritis with stemless humeral head arthroplasty including 40 hemi- (HSA) and 33 total shoulder arthroplasties (TSA). Operating times of stemless implantations were compared to 110 stemmed anatomical shoulder prostheses. Appearances of humeral radiolucencies or radiological signs of osteolysis or stress shielding were assessed on standardized radiographs. Patients' clinical outcome was evaluated using the Constant score and patients' satisfaction was documented. RESULTS: Radiological changes, detected in 37.0%, did not affect clinical outcome. Constant scores significantly improved from baseline to short and mid-term follow-up (p < 0.001). The majority of patients (96.2%) were satisfied with the procedure. No loosening of the humeral head component was detected during a mean follow-up of 58 months. Operating times were significantly shorter with stemless compared to stemmed implants (p < 0.001). CONCLUSIONS: Clinical mid-term outcome after stemless humeral head replacement was not affected by radiological changes. TRIAL REGISTRATION: The institutional review board (St. Vincent Hospital Vienna; 201212_EK01; date of issue: 11.12.2012) approved the study. The trial was registered at ClinicalTrials.gov ( NCT02754024 ). Retrospective registration.

Critical shoulder angle combined with age predict five shoulder pathologies: a retrospective analysis of 1000 cases.

BACKGROUND: Acromial morphology has previously been defined as a risk factor for some shoulder pathologies. Yet, study results are inconclusive and not all major shoulder diseases have been sufficiently investigated. Thus, the aim of the present study was to analyze predictive value of three radiological parameters including the critical shoulder angle, acromion index, and lateral acromion angle in relationship to symptomatic patients with either cuff tear arthropathy, glenohumeral osteoarthritis, rotator cuff tear, impingement, and tendinitis calcarea. METHODS: A total of 1000 patients' standardized true-anteroposterior radiographs were retrospectively assessed. Receiver-operating curve analyses and multinomial logistic regression were used to examine the association between shoulder pathologies and acromion morphology. The prediction model was derived from a development cohort and applied to a validation cohort. Prediction model's performance was statistically evaluated. RESULTS: The majority of radiological measurements were significantly different between shoulder pathologies, but the critical shoulder angle was an overall better parameter to predict and distinguish between the different pathologies than the acromion index or lateral acromion angle. Typical critical shoulder angle-age patterns for the different shoulder pathologies could be detected. Patients diagnosed with rotator cuff tears had the highest, whereas patients with osteoarthritis had the lowest critical shoulder angle. The youngest patients were in the tendinitis calcarea and the oldest in the cuff tear arthropathy group. CONCLUSIONS: The present study showed that critical shoulder angle and age, two easily assessable variables, adequately predict different shoulder pathologies in patients with shoulder complaints.

Arthroscopic management of massive rotator cuff tears: an evaluation of debridement, complete, and partial repair with and without force couple restoration.

PURPOSE: To evaluate the effectiveness of arthroscopic debridement (DB), partial (PR), and complete repair (CR) for massive rotator cuff tears (mRCT) in terms of functional and subjective parameters, and repair integrity. METHODS: For this single-centre study, 68 consecutive shoulders with mRCT involving at least three tendons and treated with arthroscopic DB (n = 23), PR (n = 22), and CR (n = 23) were included. All patients (52-81 years) were prospectively assessed before and at a mean of 45 months after surgery using functional and subjective parameters. Preoperative tendon rupture pattern and post-operative repair integrity were assessed by MRI. A coding system describing accurately rotator cuff rupture, treatment, and integrity was established. RESULTS: All treatment groups improved significantly from pre- to post-operative (P < 0.01), while preoperative parameters, except fatty degeneration, were not significantly different. However, post-operative comparisons revealed similar scores with DB (constant score, CS 65.8 ± 14.7, qDASH 24.1 ± 20.6) and PR (CS 67.5 ± 9.9, P = n.s.; qDASH 20.5 ± 14.4, P = n.s.), while CR were significantly better (CS 80.3 ± 8.9; qDASH 7.0 ± 8.7; P ≤ 0.001). Force couple restoration of PR did not significantly influence outcome. Re-tear rates with CR (29 %) were lower compared to PR (53 %). Intact CR compared to intact PR showed better CS (83.4 ± 7.3 vs. 68.5 ± 10.6, P = 0.009) and qDASH (5.4 ± 8.3 vs. 21.2 ± 9.5, P = 0.006). The vast majority of patients were satisfied with their arthroscopic procedure (DB 87 %; PR 86 %; CR 91 %). CONCLUSION: Arthroscopic DB, PR, and CR were effective in treating mRCT involving at least three tendons. Reparability of mRCT was influenced by fatty degeneration of the muscles. However, CR showed the most favourable short-term improvements. LEVEL OF EVIDENCE: IV.

Bony Regrowth and New Spur Formation as Possible Causes of Failed Distal Clavicle Excision-Mid-Term Outcomes after Revision Surgery in a Matched-Pair Analysis.

BACKGROUND: Despite high rates of successful outcomes after open and arthroscopic distal clavicle excision (DCE) for symptomatic acromioclavicular joint (ACJ) degeneration, some patients present with persistent symptoms and disabilities after surgical intervention. This study aims to compare radiological, functional, and subjective outcomes of open revision surgery after failed arthroscopic DCE to primary successful arthroscopic DCE. METHODS: In this retrospective case-control study, 10 patients who underwent open DCE revision were age- and gender-matched with 10 patients who did not require revision surgery after DCE. Radiographic evaluation included presence of acromioclavicular spurs and acromioclavicular joint distance. Functional and subjective outcomes were assessed using the CS, SSV, SST, VAS for pain, patient's satisfaction, ASES and quick DASH score. RESULTS: At the latest postoperative follow-up (case: 57.3 ± 19.2 months; control: 63.5 ± 16.3 months), spur formation was detected in twice as many cases in the revision group, while acromioclavicular distance showed no significant difference. However, a significant bony regrowth was noticed in the revision group between revision surgery and latest follow-up, with a decrease of the acromioclavicular distance from 9.2 ± 1.6 mm to 5.9 ± 4.6 mm (p = 0.026) and a development of new spur formations in 30% of cases. There were no significant differences in overall CS between the revision and control group (p = 0.174) at final follow-up, but the control group scored significantly higher in the CS subgroups pain (p = 0.012) and internal rotation (p = 0.016). Mean SSV was significantly lower in the revision (65.5 ± 22.3%) compared to the control group (85.9 ± 16.4%; p = 0.031). CONCLUSIONS: Bony regrowth at the distal clavicle presenting as postoperative AC-distance narrowing and new spur formation was observed more distinctly in the revision group. Despite a slight increase in postoperative outcomes after revision surgery, subjective satisfaction and recalcitrant pain remain a concern. LEVEL OF EVIDENCE: Therapeutic Level III, retrospective case-control study.

Comparison of Outcomes After Arthroscopic Superior Capsule Reconstruction Versus Arthroscopic Partial Repair or Arthroscopic Debridement for Irreparable Rotator Cuff Tears.

Background: Arthroscopic superior capsule reconstruction (SCR), arthroscopic partial repair (PR), and arthroscopic debridement (DB) are valid treatment options for irreparable rotator cuff (RC) tears. Purpose/Hypothesis: The purpose of this study was to compare clinical, functional, and radiological outcomes of arthroscopic SCR with arthroscopic PR and arthroscopic DB in patients with irreparable posterosuperior RC tears. It was hypothesized that SCR would lead to superior clinical and functional outcomes compared with PR or DB. Study Design: Cohort study; Level of evidence, 3. Methods: Clinical and functional outcomes of this single-center retrospective study included range of motion, strength, and the age- and sex-adjusted Constant-Murley score. Patient-reported outcome measures (PROMs) involved the quick Disabilities of the Arm, Shoulder and Hand score, the Subjective Shoulder Value, and the visual analog scale for pain. Graft and repaired tendon integrity was evaluated by magnetic resonance imaging (MRI) at 12 months of follow-up. Results: In total, 57 patients treated with SCR (n = 20), PR (n = 17), and DB (n = 20) were included. The mean clinical follow-up was 33.8 ± 17.9 months. Preoperative clinical and functional characteristics were comparable among the 3 groups. The range of motion and clinical and functional scores of all 3 groups significantly improved from pre- to postoperatively. Postoperative PROMs showed no differences among all 3 study groups. SCR revealed significantly higher postoperative strength compared with PR (P = .001) and DB (P = .004). Postoperative MRI revealed a rerupture in 4 patients with SCR (20%). Postoperative MRI showed a rerupture in 9 patients with PR ( 53%). Fatty muscle infiltration of the supraspinatus and infraspinatus significantly progressed within all 3 study groups in postoperative MRI scans. No clinical and functional differences were observed between intact and reruptured PR. Conclusion: Patients who underwent SCR had better postoperative strength recovery than patients who underwent PR or DB.

All-arthroscopic implant-free iliac crest bone grafting: new technique and case report.

Glenoid bone loss is a recognized risk for recurrent instability. Open J-graft augmentation has been reported as a well-established procedure for anterior shoulder instability. Few data are available on arthroscopic techniques for the repair of bony Bankart lesions. We describe an all-arthroscopic implant-free iliac crest bone grafting technique and present the case of a 32-year-old hockey player who underwent glenoid reconstruction using this novel arthroscopic repair technique after 2 failed soft-tissue procedures. After 13 months, the patient reached nearly full range of motion with a slight loss of external rotation. The computed tomography scan showed a restoration of the glenoid cavity and complete healing of the graft.

Superiority of bridging techniques with medial fixation on initial strength.

PURPOSE: The purpose of our study was to evaluate the initial fixation strength of bridging techniques compared to other suture techniques for rotator cuff repair using a biomechanical animal model, which incorporated pretesting of intact tendons. METHODS: Seventy-six fresh bovine shoulders were used for testing seven suture configurations including simple suture (SS), mattress suture (MS), Mason-Allen (MA), modified double row (mDR), SpeedBridge (SpB), SpeedBridge with medial fixation (mSpB), and double-mattress SutureBridge (dmSuB) techniques. Cyclic loading was performed with all intact bone-tendon complex before (pretest) and after repair of the tendon (main test) at the level of 10 and 180 N at 100 Hz with displacement-controlled ramps of ± 33 mm/s. The pretest was stopped after 200 cycles. For the main test, the loading scheme was continued for a maximum of 500 cycles or until failure. RESULTS: The mean elongation of all 76 intact tendons measured at the pretest was 3.8 ± 0.6 mm (2.4-5.4 mm). No differences of gap formations at the 1st cycle were detected between SS, MS, MA, and mDR. SpB showed significant higher gap formations compared to all other suture techniques (p = 0.001). No significant differences were detected between mSpB and dmSuB, whereas both techniques were significant different when compared to the other groups (p < 0.05). CONCLUSIONS: In this study, results showed that bridging techniques with medial fixations have superior initial repair strength compared to other suture techniques. Knowledge of initial fixation strength of rotator cuff repair techniques may be of informative value to the surgeon.

Long head of the biceps intra-articular tenotomy using needle arthroscopy under local anesthesia: preliminary results and technical note.

PURPOSE: Arthroscopic isolated biceps tenotomy is a procedure successfully performed in patients with degenerative rotator cuff tears which offers good clinical results. With this article, we describe the technique of biceps tenotomy with needle arthroscopy in local anesthesia and the results of first patients treated from 2018. METHODS: Thirteen patients with irreparable rotator cuff tear treated with arthroscopic needle biceps tenotomy under local anesthesia were included. Constant score and active/passive flexion were recorded preoperatively and at 3 months postoperatively. RESULTS: The average age of the patients was 71 ± 7 year old. All the patients were available for the follow-up. The Constant score significantly improved from pre- to postoperatively (44 ± 8.9 to 63.1 ± 14.2, p < 0.05). Active flexion improved from preoperatively 115 ± 24° to 145 ± 31° postoperatively (p < 0.05), while passive flexion did not significantly improve. CONCLUSION: This technique can be safely performed in the elderly patient with irreparable rotator cuff tears and pain refractory to conservative measures.

The Evolution of Reverse Total Shoulder Arthroplasty-From the First Steps to Novel Implant Designs and Surgical Techniques.

PURPOSE OF REVIEW: The purpose of this review is to summarize recent literature regarding the latest design modifications and biomechanical evolutions of reverse total shoulder arthroplasty and their impact on postoperative outcomes. RECENT FINDINGS: Over the past decade, worldwide implantation rates of reverse total shoulder arthroplasty have drastically increased for various shoulder pathologies. While Paul Grammont's design principles first published in 1985 for reverse total shoulder arthroplasty remained unchanged, several adjustments were made to address postoperative clinical and biomechanical challenges such as implant glenoid loosening, scapular notching, or limited range of motion in order to maximize functional outcomes and increase the longevity of reverse total shoulder arthroplasty. However, the adequate and stable fixation of prosthetic components can be challenging, especially in massive osteoarthritis with concomitant bone loss. To overcome such issues, surgical navigation and patient-specific instruments may be a viable tool to improve accurate prosthetic component positioning. Nevertheless, larger clinical series on the accuracy and possible complications of this novel technique are still missing.

Acromioclavicular Disk as a Potential Source of Pain in AC Joint Injuries.

BACKGROUND: Injuries of the acromioclavicular joint (ACJ) are common shoulder injuries that often lead to pain and dysfunction of the affected shoulder. Regardless of operative or nonoperative treatment, a relatively large number of patients remain symptomatic and experience pain. However, the specific source of persistent pain in the ACJ remains ambiguous. PURPOSE: To investigate the presence of sensory nerve fibers or pain-generating neurotransmitters within the intra-articular disk of the ACJ to determine its potential role as an independent pain generator in ACJ disorders. STUDY DESIGN: Descriptive laboratory study. METHODS: Twelve paired ACJs from 6 fresh human cadavers (mean age, 56 years; range, 41-82 years) were harvested and freed from surrounding soft tissues, leaving only the ACJ capsule intact. The specimens were placed in 4.5% formaldehyde fixative for a minimum of 48 hours. Coronal plane sections were obtained and demineralized in EDTA for a week, embedded in paraffin for 12 hours, and dehydrated overnight. With a rotation microtome, 2-µm sections were cut and stained with hematoxylin and eosin to investigate tissue architecture and confirm the presence of a fibrocartilaginous intra-articular disk. The sections were immunohistochemically stained with antisera against S100, neuropeptide Y (NPY), and substance P (SP) to detect for neural tissue. Additionally, a nerve fiber count per 10 high-power fields representing an area of 0.2 mm2 was conducted for S100 stains. All sections were examined for the presence of positive immunoreactivity to S100, NPY, and SP. RESULTS: The presence of a fibrocartilaginous intra-articular disk could be observed in all 12 examined ACJs. In all specimens, an immunoreactivity to S100, NPY, and SP could be observed within the superior peripheral region of the intra-articular disk. High-power field nerve counts of the S100 stains revealed a mean ± SD of 7.9 ± 2.28 nerves per 10 high-power fields (range, 4-12). CONCLUSION: The documented immunoreactivity to S100, NPY, and SP indicates the presence of somatic and autonomic nerve fibers within the intra-articular disk of the ACJ. CLINICAL RELEVANCE: Confirming the presence of nerve fibers within the intra-articular disk of the ACJ suggests that the disk itself could be an independent source of pain after injury and thus a possible explanation for recalcitrant pain after treatment.

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

BACKGROUND: Retears after rotator cuff repair (RCR) have been associated with poor clinical results. Meaningful data regarding the role of arthroscopic revision RCR are sparse thus far. PURPOSE/HYPOTHESIS: To investigate results after arthroscopic revision RCR. We hypothesized that (1) arthroscopic revision RCR would lead to improved outcomes, (2) the clinical results would be dependent on tendon integrity and (3) tear pattern, tendon involvement, and repair technique would influence clinical and structural results. STUDY DESIGN: Case series; Level of evidence 4. METHODS: During a 40-month period, 100 patients who underwent arthroscopic revision RCR were prospectively enrolled in this multicenter study. Outcomes were evaluated preoperatively, at 6 months (6M), and at 24 months (24M) using the Constant score (CS), the Oxford Shoulder Score (OSS), and the Subjective Shoulder Value (SSV). Tendon integrity at 2 years was analyzed using magnetic resonance imaging. A total of 13 patients (13%) were lost to follow-up, and 14 patients (14%) had a symptomatic retear before the 24M follow-up. RESULTS: All clinical scores improved significantly during the study period (CS: preoperative, 44 ± 16; 6M, 58 ± 22; 24M, 69 ± 19 points; OSS: preoperative, 27 ± 8; 6M, 36 ± 11; 24M, 40 ± 9 points; SSV: preoperative, 43% ± 18%; 6M, 66% ± 24%; 24M, 75% ± 22%) (P < .01). At 2 years, a retear rate of 51.8% (43/83) and a surgical revision rate of 12.6% (11/87) were observed. Mean full-thickness tear size decreased from 5.00 ± 1.61 cm2 to 3.25 ± 1.92 cm2 (P = .041). Although the Sugaya score improved from 4.5 ± 0.9 to 3.7 ± 1.4 (P = .043), tendon integrity did not correlate with better outcome scores. Previous open RCR, involvement of the subscapularis, chondral lesions of Outerbridge grade ≥2, and medial cuff failure were correlated with poorer SSV scores at 2 years (P≤ .047). Patients with traumatic retears had better CS and OSS scores at 2 years (P≤ .039). CONCLUSION: Although arthroscopic revision RCR improved shoulder function, retears were frequent but usually smaller. Patients with retears, however, did not necessarily have poorer shoulder function. Patient satisfaction at 2 years was lower when primary open RCR was performed, when a subscapularis tear or osteoarthritis was present, and when the rotator cuff retear was located at the musculotendinous junction. Patients with traumatic retears showed better functional improvement after revision.

Muscle-Specific Micro-Ribonucleic Acids miR-1-3p, miR-133a-3p, and miR-133b Reflect Muscle Regeneration After Single-Dose Zoledronic Acid Following Rotator Cuff Repair in a Rodent Chronic Defect Model.

BACKGROUND: Zoledronic acid improves bone microarchitecture and biomechanical properties after chronic rotator cuff repair (RCR) in rats. Besides the positive effects of zoledronic acid on bone mineral density and bone microarchitecture, bisphosphonates have positive effects on skeletal muscle function. PURPOSES/HYPOTHESIS: The purposes of this study were to (1) longitudinally evaluate circulating bone- and muscle-specific serum micro-ribonucleic acids (miRNAs) and (2) investigate supraspinatus muscle tissue after tenotomy and delayed RCR in a rat model. It was hypothesized that zoledronic acid would improve muscle regeneration after chronic RCR in rats. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 34 male Sprague-Dawley rats underwent unilateral (left) supraspinatus tenotomy (time point 1) with delayed transosseous RCR after 3 weeks (time point 2). All rats were sacrificed 8 weeks after RCR (time point 3). Animals were randomly assigned to 2 groups. One day after RCR, the control group was given 1 mL of subcutaneous saline solution, and the intervention group was treated with a subcutaneous single-dose of 100 µg/kg body weight of zoledronic acid. All 34 study animals underwent miRNA analysis at all 3 time points. In 4 animals of each group, histological analyses as well as gene expression analyses were conducted. RESULTS: Circulating miRNAs showed significantly different expressions between both study groups. In the control group, a significant downregulation was observed for muscle-specific miR-1-3p (P = .004), miR-133a-3p (P < .001), and miR-133b (P < .001). Histological analyses showed significantly higher rates of regenerating myofibers on the operated side (left) of both study groups compared with the nonoperated side (right; P = .002). On the nonoperated side, significantly higher rates of regenerating myofibers were observed in the intervention group compared with the control group (P = .031). The myofiber cross-sectional area revealed significantly smaller myofibers on both sides within the intervention group compared with both sides of the control group (P < .001). Within the intervention group, significantly higher expression levels of muscle development/regeneration marker genes embryonal Myosin heavy chain (P = .017) and neonatal Myosin heavy chain (P = .016) were observed on the nonoperated side compared with the operated side. CONCLUSION: An adjuvant single-dose of zoledronic acid after RCR in a chronic defect model in rats led to significant differences in bone- and muscle-specific miRNA levels. Therefore, miR-1-3p, miR-133a-3p, and miR-133b might be used as biomarkers for muscle regeneration after RCR. CLINICAL RELEVANCE: Adjuvant treatment with zoledronic acid may improve muscle regeneration after chronic RCR in humans, thus counteracting fatty muscle infiltration and atrophy.

Arthroscopic, Implant-Free Bone-Grafting for Shoulder Instability with Glenoid Bone Loss.

Anterior shoulder instability is commonly associated with injuries to the labrocapsular structures of the glenohumeral joint and with osseous glenoid defects of varying degree. If the bone defect exceeds a clinically relevant threshold, mere soft-tissue repairs result in high rates of recurrent instability and the glenoid needs to be reconstructed with osseous augmentation. The most popular techniques for glenoid reconstruction include variations of coracoid transfer or bone-block procedures; however, these procedures are not free from risks and complications, which are often related to the method of fixation1. An alternative to the widely used coracoid transfer variations or bone-block procedures is anatomic implant-free glenoid reconstruction with a J-shaped iliac-crest bone graft. After press-fit fixation, the graft undergoes a physiological remodeling process resulting in the restoration of native scapular neck morphology. Although not as widely known, the open J-bone-graft procedure has been successfully used for the treatment of glenoid bone loss for nearly 3 decades2-4. The arthroscopic J-bone-graft technique represents an innovative advancement of the open procedure. Early to midterm follow-up of the arthroscopic J-bone-graft technique has revealed excellent clinical results1. DESCRIPTION: The major steps of the procedure, which are demonstrated in the present video article, include (1) detachment of the labrocapsular ligamentous complex and preparation of the anterior aspect of the glenoid, (2) establishment of a deep anterior-inferior portal and splitting of the subscapularis tendon, (3) introduction of the "waterslide," (4) osteotomy at the scapular neck 30° relative to the glenoid surface and trial impaction, (5 and 6) harvesting and preparation of a J-shaped bicortical iliac-crest bone graft, (7) press-fit impaction of the bone graft in the prepared osteotomy over the "waterslide", and (8) capsuloligamentous repair over the graft. ALTERNATIVES: Coracoid transfer (Latarjet-Bristow), iliac-crest bone-grafting, and distal tibial allograft. RATIONALE: Although widely in use, nonanatomic coracoid transfer procedures or bone-block techniques relying on hardware fixation are associated with specific complications, including nonunion, osteolysis, coracoid fractures, hardware complications, and difficult revision1. Many of these disadvantages can be avoided by the use of anatomic implant-free glenoid reconstruction with a J-shaped iliac-crest bone graft. After press-fit fixation, the graft undergoes a physiological remodeling process that follows the law of bone adaptation to mechanical stresses described by Wolff, which ultimately results in the restoration of a nearly native anterior scapular neck morphology4. The open version of this technique has been successfully used for over 3 decades. The arthroscopic, minimally invasive variation of the J-bone-graft technique presented in this video article represents a further advancement of the anatomic nature of the procedure. EXPECTED OUTCOMES: The arthroscopic implant-free J-bone-graft technique is an alternative to other procedures widely used for the treatment of anterior glenoid bone defects. The main advantage of this technique is the avoidance of severe complications that arise from the nonanatomic reconstruction and fixation methods found with other procedures1. Early to midterm follow-up of the arthroscopic J-bone-graft technique has revealed excellent clinical results, and the traditional open technique has been in use successfully for over 3 decades2-5. Previous patients have been able to return to a variety of occupational and athletic activities including overhead, throwing, and contact sports. Return to daily living and to moderate athletic activities is usually possible within 3 months. Return to competition is allowed after 6 months2-5. IMPORTANT TIPS: •Avoid intraoperative graft fractures by applying strictly axial force during impaction.•Reduce the risk of glenoid fractures by performing an oblique osteotomy at an angle of 20° to 30° and 5 mm medial to the glenoid surface.•The postoperative physiological remodeling process determines ultimate graft fixation and glenohumeral stability. Keep this in mind when allowing return to activities.

Mid- to Long-Term Outcomes After Deep Infections After Arthroscopic Rotator Cuff Repair.

PURPOSE: To review clinical and subjective outcomes in patients with deep infections after arthroscopic rotator cuff repair. METHODS: All patients in whom deep infections developed after arthroscopic rotator cuff repair at a single center between 2002 and 2016 were retrospectively reviewed. Demographic data, clinical and microbiological findings, and treatment were analyzed. Clinical and subjective outcomes included the Constant score, visual analog scale score for pain, American Shoulder and Elbow Surgeons score, and Simple Shoulder Test score. RESULTS: Thirty patients could be identified and included in the study. The most commonly isolated pathogens were Staphylococcus epidermidis (36.7%) and Cutibacterium acnes (30.0%). In 26 of 30 patients (86.7%), the infection was treated initially with an open surgical approach, whereas 4 patients (13.3%) underwent arthroscopic revision. A transosseous rotator cuff repair could be performed in 20.0% of patients. A single reoperation was sufficient in 80% of patients, whereas 13.3% required 2 revisions and 6.7% required 3. At the final follow-up of 8.3 years (range, 4-14 years), 26 patients (1 woman and 25 men) were available for outcome evaluation. Significant improvement from the initial surgical procedure to final follow-up was detected in the Constant score (25.7 vs 65.7, P < .001), visual analog scale score for pain (7.0 vs 1.7, P < .001), American Shoulder and Elbow Surgeons score (38.0 vs 76.7, P < .001), and Simple Shoulder Test score (4.0 vs 8.3, P < .001). CONCLUSIONS: Patients with deep infections after arthroscopic rotator cuff repair showed moderate mid- to long-term outcomes. LEVEL OF EVIDENCE: Level IV, therapeutic case series.