Greater Tuberosity Fractures after RTSA: A Matched Group Analysis

Periprosthetic fractures, such as acromial and spine fractures, are known complications following implantation of reverse shoulder arthroplasty (RTSA). The entity of greater tuberosity fractures (GTF) has rarely been studied in the literature. The purpose of this study was to analyze the outcome of postoperative greater tuberosity fractures after RTSA compared to a matched control group. The main findings of this study are that a GTF after RTSA is associated with worse clinical outcome scores (mean absolute CS 50 ± 19 (p = 0.032); SSV 63% ± 26 (p = 0.022); mean force 1 kg ± 2 kg (p = 0.044)) compared with the control group (mean absolute CS 62 ± 21; SSV 77% ± 29; mean force 2 kg ± 2 kg). In terms of postoperative range of motion, the fracture group was significantly worse in terms of external rotation (17° ± 19° vs. 30° ± 19° (p = 0.029)). Internal rotation, flexion, as well as abduction of the shoulder appear to be unaffected (internal rotation GTF 4 ± 2, control group 5 ± 3 (p = 0.138); flexion GTF 102° ± 28°, control group 114° ± 27° (p = 0.160); abduction GTF 109° ± 42°, control group 120° ± 39° (p = 0.317))

Predictive factors of acromial fractures following reverse total shoulder arthroplasty: a subgroup analysis of 860 shoulders

BACKGROUND: Acromion stress fractures (ASF) or scapular spine fractures (SSF) following reverse total shoulder arthroplasty (RTSA) are common complications with impaired clinical outcome. The underlying biomechanical factors remain unclear. The aim of this study was to evaluate basic demographic and radiographic parameters predicting occurrence of different types of ASF/SSF in a large single-center study cohort. METHODS: A total of 860 RTSA (805 patients) with available minimum follow-up of 2 years were implanted between 2005 and 2018 at a tertiary academic center. All RTSA with subsequent ASF/SSF (n = 45 in 43 shoulders [42 patients, 5%]) were identified and classified as Levy I to III. Predictive demographic, surgical, and radiographic factors were evaluated for each subtype and compared to the control group (817 RTSA, 763 patients). The radiographic analysis included critical shoulder angle, lateralization shoulder angle (LSA), distalization shoulder angle (DSA), acromio-humeral distance (ACHD), acromial thickness, deltoid tuberosity index, deltoid length, and center of rotation. RESULTS: Of the 45 ASF/SSF in 42 patients, 8 were classified as Levy I, 21 as Levy II, and 16 as Levy III. Demographic analysis revealed indication as risk factor for Levy I fractures, higher American Society of Anesthesiologists score as risk for Levy type II fractures and higher age as risk factor for Levy type III fractures. None of the measured radiographic parameters were predictive for occurrence of Levy type I and Levy type II ASF. However, analysis of Levy III SSF revealed a higher postoperative LSA (89° ± 10° vs. 83° ± 9°, P = .015), a lower postoperative DSA (45° ± 8° vs. 53° ± 12°, P = .002), less distalization (ACHD of 33 ± 8 mm vs. 38 ± 10 mm, P = .049), and a more medial center of rotation preoperatively (COR-LA 16 ± 8 mm vs. 12 ± 7 mm, P = .048) as predictive radiographic factors. CONCLUSION: The present analysis showed a significant association of higher postoperative LSA, lower DSA, a lower ACHD, and higher age as predictive factor only for Levy type III fractures. Some of these factors can be surgically influenced and this knowledge can be of value for preoperative planning and surgical execution to avoid these complications

Return to Play After Surgical Treatment of High-Grade Acromioclavicular Joint Injuries in the Australian Football League

Background Acromioclavicular joint (ACJ) injuries are the second most common upper limb injuries in the Australian Football League (AFL); however, there is little evidence on the return-to-sport results after surgical stabilization of the ACJ in this sporting population. Purpose To investigate the return-to-sport time, on-field performance, and patient-reported outcomes in a series of professional AFL players after undergoing ACJ stabilization. Study Design Case series; Level of evidence, 4. Methods We conducted a retrospective case series of all AFL players who had undergone open twin-tailed dog-bone ACJ stabilization by a single surgeon between September 2013 and April 2017. Outcome measures included time to return to sport, on-field performance indicators (handballs, tackles, kicks, and AFL Fantasy and Supercoach scores), the Nottingham Clavicle Score, Oxford Shoulder Score, and the Specific Acromioclavicular Score. Patient-reported outcomes were evaluated at a minimum follow-up of 12 months. Results Of 13 senior listed AFL players who underwent twin-tailed dog-bone surgery, 9 players were included. Mean follow-up was 24.8 months (range, 5-41 months) postoperatively. Mean return-to-sport time was 8.6 weeks for injuries that occurred within the season. The number of kicks, marks, handballs, and tackles as well as AFL Supercoach and Fantasy scores did not significantly change after surgery (P > .05). Outcome measures showed a high level of patient satisfaction after surgery, with a mean Nottingham Clavicle Score of 92.2, Oxford Shoulder Score of 47.7, and the Specific Acromioclavicular Score of 7.5. Conclusion In a collective of professional AFL players with ACJ injury, our twin-tailed dog-bone technique revealed return to competitive play could be achieved at a mean of 8.6 weeks without compromising on-field performance or patient-reported pain, function, and satisfaction

Stability of novel cow-hitch suture button coracoid bone graft fixation in Latarjet procedures: a biomechanical study

BACKGROUND The Latarjet procedure is widely used to address anterior shoulder instability, especially in case of glenoid bone loss. Recently, cortical suture button fixation for coracoid transfer has been used to mitigate complications seen with screw placement. The aim of this biomechanical study was to evaluate the stability of a novel and cost-effective cow-hitch suture button technique, designed to be performed through a standard open deltopectoral approach, and compare this to a well-established double suture button technique. MATERIALS AND METHODS We randomly assigned 12 fresh frozen cadaveric shoulders to undergo the Latarjet procedure with either 4 suture button (S&N EndoButton) fixations (SB group; n = 6, age 72 ± 9.8 years) or cow-hitch suture button technique using a 1.7-mm FiberTape looped sequentially in 2 suture buttons (Arthrex Pectoralis Button) placed from anterior on the posterior glenoid (CH-SB group; n = 6, age 73 ± 9.3 years). After fixation, all shoulders underwent biomechanical testing with direct loading on the graft via a material testing system. Cyclic loading was performed for 100 cycles (10-100 N) to determine axial displacement with time; each graft was then monotonically loaded to failure. RESULTS The maximum cyclic displacement was 4.3 ± 1.6 mm for the cow-hitch suture button technique and 5.0 ± 1.7 mm for the standard double suture button technique (P = .46). Ultimate load to failure and stiffness were, respectively, 190 ± 82 N and 221 ± 124 N/mm for the CH-SB technique and 172 ± 48 N and 173 ± 34 N/mm for the standard double SB technique (P = .66 and .43). The most common failure mode was suture cut-through at the anteroinferior aspect of the glenoid for both fixation groups. CONCLUSIONS The cow-hitch suture button technique resulted in a similar elongation, stiffness, and failure load compared to an established double suture button technique. Therefore, this cost-effective fixation may be an alternative, eligible for open approaches, to the established double suture button techniques

Acromial Morphology and Its Relation to the Glenoid Is Associated with Different Partial Rotator Cuff Tear Patterns

The pathogenesis of subacromial impingement syndrome is controversially discussed. Assuming that bursal sided partial tears of the supraspinatus tendons are rather the result of a direct subacromial impact, the question arises whether there is a morphological risk configuration of the acromion and its spatial relation to the glenoid. Patients who underwent arthroscopic repair of either a partial articular supraspinatus tendon avulsion (PASTA) or bursal-sided supraspinatus tear (BURSA) were retrospectively allocated to two groups. Various previously described and new omometric parameters on standard anteroposterior and axial shoulder radiographs were analyzed. We hypothesized that acromial shape and its spatial relation to the glenoid may predispose to a specific partial supraspinatus tendon tear pattern. The measurements included the critical shoulder angle (CSA), the acromion index (AI), Bigliani acromial type and the new short sclerotic line, acromioclavicular offset angle (ACOA), and AC offset. The ratio length/width of acromion and the medial acromial offset were measured on axial radiographs. A total of 73 patients were allocated to either PASTA (n = 45) or BURSA (n = 28). The short sclerotic line showed a statistically significant difference between PASTA and BURSA (16.2 mm versus 13.1 mm, p = 0.008). The ratio acromial width/length was statistically significant (p = 0.021), with BURSA having slightly greater acromial length (59 vs. 56 mm). The mean acromial offset was 42.9 mm for BURSA vs. 37.7 mm for PASTA (p = 0.021). ACOA and AC offset were both higher for BURSA, without reaching statistical significance. The CSA did not differ significantly between PASTA and BURSA (33.73° vs. 34.56°, p = 0.062). The results revealed an association between a narrow acromial morphology, increased medial offset of the acromion in relation to the glenoid, and the presence of a short sclerotic line in the anteroposterior radiograph in bursal-sided tears of the supraspinatus tendon. Assuming that bursal-sided tears are rather the result of a direct conflict of the tendon with the undersurface of the acromion, this small subgroup of patients presenting with impingement syndrome might benefit from removing a harming acromial spur

Reverse Total Shoulder Arthroplasty for Proximal Humeral Fractures and Sequalae Compared to Non-Fracture Indications: A Matched Cohort Analysis of Outcome and Complications

BACKGROUND: With the increase in utility and popularity of the reverse total shoulder arthroplasty (RTSA) within the last decades, indications for RTSA have expanded. As well as the established indications such as cuff tear arthropathy and massive irreparable rotator cuff tears, RTSA for complex proximal humeral fractures in elderly patients has been proven to be a reliable treatment option. METHODS: A prospectively enrolled RTSA database of 1457 RTSAs implanted between September 2005 and November 2020 was reviewed. Patients treated with RTSA for a complex proximal humerus fracture and fracture sequalae (F-RTSA) were 1:1 matched with a group of patients who were treated electively with RTSA for indications other than a fracture (E-RTSA). Matching criteria included sex, age, length of follow-up and body mass index. Evaluation after a minimum of 2 years follow-up included evaluation of the absolute and relative Constant-Murley score (aCS; rCS), subjective shoulder value (SSV), range of motion (ROM) assessment and complications. RESULTS: Each of the matched cohorts comprised 134 patients with a mean follow-up of 58 ± 41 months for the fracture group and 58 ± 36 months for the elective group. The mean age for both groups was 69 ± 11 years in the F-RTSA and 70 ± 9 years for the E-RTSA group. There were no significant differences in clinical outcome measures including aCS, rCS and SSV (p > 0.05). There was a significant difference in mean active external rotation with 20° ± 18° in the F-RTSA group compared with 25° ± 19° in the E-RTSA group (p = 0.017). The complication rate was not significantly different, with 41 complications in 36 shoulders in the F-RTSA and 40 complications in 32 shoulders in the E-RTSA group (p = 0.73). The main complication for the F-RTSA group was dislocation of the greater tuberosity (6%), whereas acromial fractures (9%) were the leading complication in the E-RTSA group. There was also no significant difference in revision rate comparing F-RTSA with E-RTSA (10% vs. 14%; p = 0.25). CONCLUSIONS: RTSA for complex proximal humeral fractures and its sequalae leads to a comparable clinical outcome as that for patients treated electively with RTSA for indications other than fracture. There was, however, a significant difference in active external rotation, with inferior rotation in patients undergoing RTSA for fracture. This valuable information can help in requesting informed consent of patients with proximal humeral fractures

Fixationssysteme und Techniken zur arthroskopischen Rotatorenmanschettenrekonstruktion : Evidenz im Jahr 2021

Arthroskopische Rotatorenmanschettenrekonstruktionen wurden initial mit einer einreihigen („single row“) Technik beschrieben. Im Rahmen technischer Weiterentwicklungen der arthroskopischen Chirurgie wurden diverse Techniken zur zweireihigen („double row“), transossären und transossär-äquivalenten Sehnenfixation entwickelt, nicht zuletzt durch eine zunehmende Verbreitung knotenloser Anker. Die klinischen Ergebnisse zeigen keine relevanten Unterschiede zwischen den jeweiligen Techniken. Biomechanisch sind zweireihige Rekonstruktionen jedoch durch Vergrößerung der Kontaktfläche an der Insertionsstelle und der erreichten Stabilität überlegen, insbesondere mit medial geknoteten Fäden, welche in eine laterale Reihe als sog. Suture-Bridge abgespannt werden. Klassischerweise wurden Schraubanker aus Metall für eine arthroskopische Sehnenfixierung verwendet. Im Laufe der letzten Jahre wurde das Anker-Portfolio jedoch durch moderne bioresorbierbare und nichtresorbierbare (PEEK) Schraub- und Einschlaganker sowie auch um reine Fadenanker (All-suture) erweitert. Ein allgemeingültiger Goldstandard für die Ankerverwendung existiert bis dato nicht, wobei die meisten gängigen Anker – zumindest bei guter Knochenqualität – Arthroskopische Rotatorenmanschettenrekonstruktionen wurden initial mit einer einreihigen („single row“) Technik beschrieben. Im Rahmen technischer Weiterentwicklungen der arthroskopischen Chirurgie wurden diverse Techniken zur zweireihigen („double row“), transossären und transossär-äquivalenten Sehnenfixation entwickelt, nicht zuletzt durch eine zunehmende Verbreitung knotenloser Anker. Die klinischen Ergebnisse zeigen keine relevanten Unterschiede zwischen den jeweiligen Techniken. Biomechanisch sind zweireihige Rekonstruktionen jedoch durch Vergrößerung der Kontaktfläche an der Insertionsstelle und der erreichten Stabilität überlegen, insbesondere mit medial geknoteten Fäden, welche in eine laterale Reihe als sog. Suture-Bridge abgespannt werden. Klassischerweise wurden Schraubanker aus Metall für eine arthroskopische Sehnenfixierung verwendet. Im Laufe der letzten Jahre wurde das Anker-Portfolio jedoch durch moderne bioresorbierbare und nichtresorbierbare (PEEK) Schraub- und Einschlaganker sowie auch um reine Fadenanker (All-suture) erweitert. Ein allgemeingültiger Goldstandard für die Ankerverwendung existiert bis dato nicht, wobei die meisten gängigen Anker – zumindest bei guter Knochenqualität – ausreichende Stabilität gewährleisten. Beim Nahtmaterial kam es ebenso zu relevanten Weiterentwicklungen, sodass dem Versagen der Nähte heutzutage weniger Bedeutung zukommt. Das Aufkommen von bandartigem Nahtmaterial (Tapes) konnte in diversen biomechanischen Studien seine Überlegenheit nachweisen, jedoch ist bei geknoteten Techniken mit Tapes aufgrund des womöglich negativen Einflusses durch größere Knoten Vorsicht geboten. Nicht zuletzt ist die mediale Stichposition möglichst nahe des Rotatorenkabels von großer Bedeutung, da der häufigste Versagensmechanismus einer Rotatorenmanschettenrekonstruktion mit modernem Naht- und Ankermaterial weiterhin ein Hindurchschneiden der Fäden durch das vorgeschädigte Sehnengewebe ist. = Arthroscopic rotator cuff repair was originally described with a single row technique. With technical advances in arthroscopic surgery various techniques for a double row, transosseous and transosseous-equivalent (TOE) tendon fixation were developed, especially with increasing use of knotless suture anchors. The clinical results show significantly different results with respect to the technique applied; however, biomechanical data could demonstrate improved footprint coverage and mechanical strength of double row reconstruction techniques. Techniques with a combination of medial row mattress sutures and a knotless lateral row in a suture bridge technique (modified TOE) are superior to fully knotless double row repair. Metal screw-in anchors were originally used in the first decade of arthroscopic rotator cuff repair; however, the portfolio has been substantially expanded over the recent years as resorbable and non-resorbable push-in and screw-in anchors as well as all-suture anchors have been introduced. No generally valid gold standard for anchor usage exists to date but most available anchors offer sufficient biomechanical strength, at least in good bone quality. Substantial improvements could also be achieved in the field of suture material available for rotator cuff repair, which is no longer the weak point of the construct in terms of suture breakage. The development of tape-type sutures could demonstrate biomechanical superiority in several studies; however, caution is advised for knotted techniques with the use of tapes due to possible negative effects of the bigger knot size. As the most frequent failure mode in arthroscopic rotator cuff repair remains suture material cutting through the damaged tendon, it should be highlighted that a stitch position just medial to the rotator cable provides the strongest suture hold

Incidence, radiographic predictors and clinical outcome for acromial stress reaction and acromial fractures in reverse total shoulder arthroplasty

INTRODUCTION Acromial and scapular spine fractures (ASF) are known complications following implantation of Reverse Total Shoulder Arthroplasty (RTSA). The entity of acromial stress reaction (ASR) without fracture has recently been described. The purpose of this study was to analyze the incidence, radiographic predictors, treatment options, healing rate and clinical outcome of ASF and ASR compared to a control group. METHODS A total of 854 primary RTSAs were implanted between 2005 and 2018 in a single shoulder unit of a tertiary referral hospital and retrospectively reviewed for the incidence of ASF and ASR. ASR was defined as pain at the acromion or scapular spine after fracture exclusion on CT scans. The ASF group was matched to a control group. Preoperative and postoperative radiographs were analyzed for radiographic predictors of ASF or ASR. The impact of ASF and ASR, operative versus non-operative treatment and fracture union on clinical outcome (Constant-Murley Score, Subjective Shoulder Value and range of motion) with minimum follow-up of 2 years was analyzed. RESULTS A total of 46 ASF (5.4 %) in 44 patients and 44 ASR (5.2%) in 43 patients were detected at a mean of 16 ± 24 months and 20±23 months postoperative, respectively. Predictive radiographic factors were an increased critical shoulder angle (CSA) and lateralization shoulder angle (LSA). The overall union rate was 55% (22/40) but significantly higher following operative treatment (9/11, 82%) compared to non-operative treatment (13/29, 45%). Patients with ASF/ASR demonstrated inferior clinical outcome (CS 44 ± 21 and 48 ± 18; SSV 52 ± 25 and 57 ± 27) compared to the control group (CS 66 ± 14; SSV: 82 ± 22) independent of bony union or treatment at mean of 59 ± 33 months (ASF) and 61 ± 38 months (ASR). CONCLUSION ASF and ASR are frequent complications following RTSA implantation with similar poor clinical outcome measures. The healing rate was shown to be much higher with a surgical approach. Nevertheless, fracture consolidation does not result in better clinical outcomes compared with nonunion

Fixation of distal clavicle fractures with coracoclavicular instability: a comparative biomechanical study in human cadavers

Background The need for coracoclavicular (CC) stabilization in the fixation of fractures with CC instability (Neer type IIB and V) was biomechanically demonstrated by higher construct strength than isolated locking plate osteosynthesis. It was the purpose of this study to prove noninferiority of the new cow-hitch suture repair technique compared with the well-established suture tape double-button fixation with regard to overall fixation strength and cyclic loading properties. Methods Twelve human cadaver shoulders (7 right and 5 left) were matched for sex and age (mean age: 75 ± 5 years). An oblique parasagittal fracture line 20 mm medial to the acromioclavicular joint line was created, and the CC ligaments were dissected. Six shoulders were reconstructed by a double FiberTape fixation with two suture buttons (group DB), and the remaining six shoulders by a cow-hitch suture repair using a double FiberWire with only coracoid button fixation (group CH). Both reconstruction techniques were tested in a servo-hydraulic material testing machine for cyclic displacement (mm), stiffness (N/mm), and maximum load-to-failure (N) after 500 cycles at 3 mm/s and inferosuperior load between 15 and 70 N. Superior fragment displacement in space was recorded using a MicroScribe digitizer. Results There were no statistically significant differences regarding cyclic displacement (group DB: 0.7 mm; group CH: 1.3 mm; P = .36), stiffness (group DB: 177 N/mm; group CH: 116 N/mm; P = .17), maximum load-to-failure (group DB: 560 N; group CH: 492 N; P = .59), and superior displacement in space of the medial fragment (group DB: 3.2 mm; group CH: 1.6 mm; P = .48). Conclusion Fixation of unstable distal clavicle fractures using a double FiberWire cow-hitch suture repair with isolated coracoid button fixation for stand-alone CC stabilization resulted in similar biomechanical properties to a double-suture button fixation with FiberTapes while avoiding prominent clavicular implants

Biomechanical Analysis of Posterior Open-Wedge Osteotomy and Glenoid Concavity Reconstruction Using an Implant-Free, J-Shaped Iliac Crest Bone Graft

BACKGROUND Posterior open-wedge osteotomy and glenoid reconstruction using a J-shaped iliac crest bone graft showed promising clinical results for the treatment of posterior instability with excessive glenoid retroversion and posteroinferior glenoid deficiency. PURPOSE To evaluate the biomechanical performance of the posterior J-shaped graft to restore glenoid retroversion and posteroinferior deficiency in a cadaveric shoulder instability model. STUDY DESIGN Controlled laboratory study. METHODS A posterior glenoid open-wedge osteotomy was performed in 6 fresh-frozen shoulders, allowing the glenoid retroversion to be set at 0°, 10°, and 20°. At each of these 3 preset angles of glenoid retroversion, the following conditions were simulated: (1) intact joint, (2) posterior Bankart lesion, (3) 20% posteroinferior glenoid deficiency, and (4) posterior J-shaped graft (at 0° of retroversion). With the humerus in the Jerk position (60° of glenohumeral anteflexion, 60° of internal rotation), stability was evaluated by measuring posterior humeral head (HH) translation (in mm) and peak translational force (in N) to translate the HH over 25% of the glenoid width. Glenohumeral contact patterns were measured using pressure-sensitive sensors. Fixation of the posterior J-graft was analyzed by recording graft micromovements during 3000 cycles of 5-mm anteroposterior HH translations. RESULTS Reconstructing the glenoid with a posterior J-graft to 0° of retroversion significantly increased stability compared with a posterior Bankart lesion and posteroinferior glenoid deficiency in all 3 preset degrees of retroversion (P < .05). There was no significant difference in joint stability comparing the posterior J-graft with an intact joint at 0° of retroversion. The posterior J-graft restored mean contact area and contact pressure comparable with that of the intact condition with 0° of retroversion (222 vs 223 mm$^{2}$, P = .980; and 0.450 vs 0.550 MPa, P = .203). The mean total graft displacement after 3000 cycles of loading was 43 ± 84 µm, and the mean maximal mediolateral graft bending was 508 ± 488 µm. CONCLUSION Biomechanical analysis of the posterior J-graft demonstrated reliable restoration of initial glenohumeral joint stability, normalization of contact patterns comparable with that of an intact shoulder joint with neutral retroversion, and secure initial graft fixation in the cadaveric model. CLINICAL RELEVANCE This study confirms that the posterior J-graft can restore stability and glenohumeral loading conditions comparable with those of an intact shoulder