Intact revision rotator cuff repair stabilizes muscle atrophy and fatty infiltration after minimum follow up of two years.

BACKGROUND: The extent of fatty infiltration and rotator cuff (RC) atrophy is crucial for the clinical results after rotator cuff repair (RCR). The purpose of this study was to evaluate changes in fatty infiltration and RC atrophy after revision RCR and to correlate them with functional outcome parameters. METHODS: Patients who underwent arthroscopic revision RCR for symptomatic recurrent full-thickness tear of the supraspinatus tendon between 2008 and 2014 and were retrospectively reviewed with a minimum follow up of 2 years. Magnetic resonance imaging (MRI) was performed pre- and postoperatively to assess 1) tendon integrity after revision RCR according to Sugaya classification, (2) RC atrophy according to Thomazeau classification, and (3) fatty infiltration according to Fuchs MRI classification. Constant score (CS) and the American Shoulder and Elbow Surgeon (ASES) score were used to correlate functional outcome, tendon integrity, and muscle degeneration. RESULTS: 19 patients (17 males and 2 females) with a mean age of 57.5 years (range, 34 to 72) were included into the study at a mean follow-up of 50.3 months (range, 24 - 101). At final evaluation, 9 patients (47%) presented with intact RCR and 10 patients (53%) suffered a re-tear after revision repair. No progress of fatty infiltration was observed postoperatively in the group with intact RC, atrophy progressed in only 1 out of 9 patient (11%). Fatty infiltration progressed in 5/10 patients (50%) and RC atrophy increased in 2/10 patients (20%) within the re-tear group. CS (42.7 ± 17.7 preop, 65.2 ± 20.1 postop) and ASES (47.7 ± 17.2 preop, 75.4 ± 23.7 postop) improved significantly from pre- to postoperatively (p < 0.001). A positive correlation between fatty infiltration and RC integrity was detected (r = 0.77, p < 0.01). No correlation between clinical outcome and tendon integrity or RC atrophy was observed. CONCLUSION: Arthroscopic revision RCR leads to reliable functional outcomes even in case of a recurrent RC retear. An intact RCR maintains the preoperative state of fatty infiltration and muscle atrophy but does not lead to muscle regeneration. LEVEL OF EVIDENCE: Level IV; Therapeutic study.

Superior Capsular Reconstruction Partially Restores Native Glenohumeral Joint Loads in a Dynamic Biomechanical Shoulder Model.

PURPOSE: To evaluate the effect of an irreparable posterosuperior rotator cuff tear (PSRCT) on glenohumeral joint loads and to quantify improvement after superior capsular reconstruction (SCR) using an acellular dermal allograft. METHODS: Ten fresh-frozen cadaveric shoulders were tested using a validated dynamic shoulder simulator. A pressure mapping sensor was placed between the humeral head and glenoid surface. Each specimen underwent the following conditions: (1) native, (2) irreparable PSRCT, and (3) SCR using a 3-mm-thick acellular dermal allograft. Glenohumeral abduction angle (gAA) and superior humeral head migration (SM) were measured using 3-dimensional motion-tracking software. Cumulative deltoid force (cDF) and glenohumeral contact mechanics, including glenohumeral contact area and glenohumeral contact pressure (gCP), were assessed at rest, 15°, 30°, 45°, and maximum angle of glenohumeral abduction. RESULTS: The PSRCT resulted in a significant decrease of gAA along with an increase in SM, cDF, and gCP (P < .001, respectively). SCR did not restore native gAA (P < .001); however, SM was significantly reduced (P < .001). Further, SCR significantly reduced deltoid forces at 30° (P = .007) and 45° of abduction (P = .007) when compared with the PSRCT. SCR did not restore native cDF at 30° (P = .015), 45° (P < .001), and maximum angle (P < .001) of glenohumeral abduction. Compared with the PSRCT, SCR resulted in a significant decrease of gCP at 15° (P = .008), 30° (P = .002), and 45° (P = .006). However, SCR did not completely restore native gCP at 45° (P = .038) and maximum abduction angle (P = .014). CONCLUSIONS: In this dynamic shoulder model, SCR only partially restored native glenohumeral joint loads. However, SCR significantly decreased glenohumeral contact pressure, cumulative deltoid forces, and superior migration, while increasing abduction motion, when compared with the posterosuperior rotator cuff tear. CLINICAL RELEVANCE: These observations raise concerns regarding the true joint-preserving potential of SCR for an irreparable posterosuperior rotator cuff tear, along with its ability to delay progression of cuff tear arthropathy and eventual conversion to reverse shoulder arthroplasty.

A shallow morphology of the intertubercular groove is associated with medial and bilateral but not lateral pulley lesions.

PURPOSE: To investigate the influence of intertubercular groove (IG) morphology on the development of different types of biceps reflection pulley (BRP) injuries. METHODS: A consecutive cohort of 221 patients with ventral shoulder pain and a preoperative diagnosis suspecting BRP injury, who underwent arthroscopy, was retrospectively reviewed. The presence or absence as well as type of pulley injury (medial, lateral or bilateral) was confirmed arthroscopically. The intertubercular groove was evaluated on MRIs after triplanar reconstruction of the axial plane. IG depth, width, medial wall angle (MWA), lateral wall angle (LWA) and total opening angle (TOA) were measured. IG depth and width were expressed in relation to the humeral head diameter. Measurements were performed by two clinicians independently and averaged. RESULTS: Of 166 included patients 43 had bilateral, 65 medial and 38 lateral BRP lesions. 20 patients had intact BRPs and represented the control group. The intra-class correlation coefficient of measurements was 0.843-0.955. Patients with a medial or bilateral BRP injury had a flatter MWA (38.8° or 40.0° vs. 47.9°, p < 0.001), wider TOA (96.1° or 96.6° vs. 82.6°, p < 0.001), greater width (12.5 or 12.3 vs. 10.8 mm, p = 0.013) and shallower depth (5.5 or 5.4 vs. 6.2 mm, p < 0.001) than the control group. Conversely, the IG morphology of those with lateral BRP injuries did not differ significantly from the control group. The odds ratio for a medial or bilateral BRP injury when the TOA exceeded 95° was 6.8 (95% confidence interval 3.04-15.2). CONCLUSION: A dysplastic type of IG morphology with a wide TOA, flat MWA, decreased depth and increased width is associated with the presence of medial and bilateral BRP injuries. A TOA of > 95° increases the likelihood of a medial or bilateral BRP injury 6.8-fold. Lateral BRP injuries are not associated with dysplastic IG morphology. Concomitant LHBT surgery may, therefore, not always be necessary during isolated supraspinatus tendon repair. LEVEL OF EVIDENCE: Level III.

Influence of sportive activity on functional and radiographic outcomes following reverse total shoulder arthroplasty: a comparative study.

BACKGROUND: The purpose of the present study was to compare the functional and radiographic outcomes following reverse total shoulder arthroplasty (RTSA) in a senior athletic and non-athletic population. MATERIAL AND METHODS: In this retrospective cohort study, patients who underwent RTSA between 06/2013 and 04/2018 at a single institution were included. Minimum follow-up was 2 years. A standardized questionnaire was utilized for assessment of patients' pre- and postoperative physical fitness and sportive activity. Patients who resumed at least one sport were assigned to the athletic group, while patients who ceased participating in sports were assigned to the non-athletic group. Postoperative clinical outcome measures included the Constant score (CS), American Shoulder and Elbow Surgeons (ASES) score, Simple Shoulder Test (SST), and visual analog scale (VAS) for pain. Active shoulder range of motion (ROM) and abduction strength were assessed. Radiographic evaluation was based on a standardized core set of parameters for radiographic monitoring of patients following shoulder arthroplasty. RESULTS: Sixty-one of 71 patients (85.9%; mean age: 72.1 ± 6.6 years) were available for clinical and radiographic follow-up at a mean of 47.1 ± 18.1 months. Thirty-four patients (55.7%) were assigned to the athletic group and 27 patients (44.3%) to the non-athletic group. The athletic group demonstrated significantly better results for CS (P = 0.002), ASES score (P = 0.001), SST (P = 0.001), VAS (P = 0.022), active external rotation (P = 0.045) and abduction strength (P = 0.016) compared to the non-athletic group. The overall rate of return to sport was 78.0% at an average of 5.3 ± 3.6 months postoperatively. Incomplete radiolucent lines (RLL) around the humeral component were found significantly more frequently in the athletic group compared to the non-athletic group (P = 0.019), whereas the occurrence of complete RLLs around the implant components was similar (P = 0.382). Scapular notching was observed in 18 patients (52.9%) of the athletic group and 12 patients (44.9%) of the non-athletic group (P = 0.51). The overall rate for revision surgery was 8.2%, while postoperative complications were encountered in 3.3% of cases. CONCLUSION: At mid-term follow-up, the athletic population demonstrated significantly better clinical results following RTSA without a higher rate of implant loosening and scapular notching when compared to non-athletic patients. However, incomplete radiolucency around the humeral component was observed significantly more often in the athletic group. LEVEL OF EVIDENCE: III.

Current concepts in acromioclavicular joint (AC) instability - a proposed treatment algorithm for acute and chronic AC-joint surgery.

BACKGROUND: There exists a vast number of surgical treatment options for acromioclavicular (AC) joint injuries, and the current literature has yet to determine an equivocally superior treatment. AC joint repair has a long history and dates back to the beginning of the twentieth century. MAIN BODY: Since then, over 150 different techniques have been described, covering open and closed techniques. Low grade injuries such as Type I-II according to the modified Rockwood classification should be treated conservatively, while high-grade injuries (types IV-VI) may be indicated for operative treatment. However, controversy exists if operative treatment is superior to nonoperative treatment, especially in grade III injuries, as functional impairment due to scapular dyskinesia or chronic pain remains concerning following non-operative treatment. Patients with a stable AC joint without overriding of the clavicle and without significant scapular dysfunction (Type IIIA) may benefit from non-interventional approaches, in contrast to patients with overriding of the clavicle and therapy-resistant scapular dysfunction (Type IIIB). If these patients are considered non-responders to a conservative approach, an anatomic AC joint reconstruction using a hybrid technique should be considered. In chronic AC joint injuries, surgery is indicated after failed nonoperative treatment of 3 to 6 months. Anatomic AC joint reconstruction techniques along with biologic augmentation (e.g. Hybrid techniques, suture fixation) should be considered for chronic high-grade instabilities, accounting for the lack of intrinsic healing and scar-forming potential of the ligamentous tissue in the chronic setting. However, complication and clinical failure rates remain high, which may be a result of technical failures or persistent horizontal and rotational instability. CONCLUSION: Future research should focus on addressing horizontal and rotational instability, to restore native physiological and biomechanical properties of the AC joint.

Reliable Clinical and Sonographic Outcomes of Subpectoral Biceps Tenodesis Using an All-Suture Anchor Onlay Technique.

PURPOSE: To evaluate the clinical outcomes and structural integrity of primary subpectoral biceps tenodesis using an all-suture anchor onlay technique for long head of the biceps (LHB) tendon pathology. METHODS: We conducted a retrospective case series with prospectively collected data of patients who underwent primary, isolated subpectoral biceps tenodesis with a single all-suture anchor onlay fixation between March 2017 and March 2019. Outcomes were recorded at a minimum follow-up of 12 months based on assessments of the American Shoulder and Elbow Surgeons (ASES) score, LHB score, and elbow flexion strength and supination strength measurements. The integrity of the tenodesis construct was evaluated using ultrasound. RESULTS: Thirty-four patients were available for clinical and ultrasound examination at a mean follow-up of 18 ± 5 months. The mean ASES score significantly improved from 51.0 ± 14.2 points preoperatively to 89.8 ± 10.5 points postoperatively (P < .001). The minimal clinically important difference for the ASES score was 8.7 points, which was exceeded by 31 patients (91.2%). The mean postoperative LHB score was 92.2 ± 8.3 points. Regarding subcategories, an average of 47.2 ± 6.3 points was reached for "pain/cramps"; 26.4 ± 6.1 points, "cosmesis"; and 18.6 ± 2.6 points, "elbow flexion strength." Both elbow flexion strength and supination strength were similar compared with the nonoperated side (P = .169 and P = .210, respectively). In 32 patients, ultrasound examination showed an intact tenodesis construct, whereas 2 patients (5.9%) sustained failure of the all-suture anchor fixation requiring revision. CONCLUSIONS: Primary subpectoral biceps tenodesis using an all-suture anchor onlay technique for pathology of the LHB tendon provides reliable clinical results and a relatively low failure rate (5.9%). LEVEL OF EVIDENCE: Level IV, case series.

Low rate of substantial loss of reduction immediately after hardware removal following acromioclavicular joint stabilization using a suspensory fixation system.

PURPOSE: To evaluate immediate loss of reduction in patients undergoing hardware removal after arthroscopically assisted acromioclavicular (AC) joint stabilization using a high-tensile suture tape suspensory fixation system and to identify risk factors associated with immediate loss of reduction. MATERIALS AND METHODS: Twenty-two consecutive patients with a mean age of 36.4 ± 12.6 years (19-56), who underwent hardware removal 18.2 ± 15.0 months following arthroscopically assisted stabilization surgery using a suspensory fixation system for AC joint injury between 01/2012 and 01/2021 were enrolled in this retrospective monocentric study. The coracoclavicular distance (CCD) as well as the clavicular dislocation/acromial thickness (D/A) ratio were measured on anterior-posterior radiographs prior to hardware removal and immediately postoperatively by two independent raters. Loss of reduction, defined as 10% increase in the CCD, was deemed substantial if the CCD increased 6 mm compared to preoperatively. Constitutional and surgical characteristics were assessed in a subgroup analysis to detect risk factors associated with loss of reduction. RESULTS: Postoperatively, the CCD significantly increased from 12.6 ± 3.7 mm (4.8-19.0) to 14.5 ± 3.3 mm (8.7-20.6 mm) (p < 0.001) while the D/A ratio increased from 0.4 ± 0.3 (- 0.4-0.9) to 0.6 ± 0.3 (1.1-0.1) (p = 0.034) compared to preoperatively. In 10 cases (45%), loss of reduction was identified, while a substantial loss of reduction (> 6 mm) was only observed in one patient (4.5%). A shorter time interval between index stabilization surgery and hardware removal significantly corresponded to immediate loss of reduction (11.0 ± 5.6 vs. 30.0 ± 20.8 months; p = 0.007), as hardware removal within one year following index stabilization was significantly associated with immediate loss of reduction (p = 0.027; relative risk 3.4; odds ratio 11.67). CONCLUSIONS: Substantial loss of reduction after hardware removal of a high-tensile suture tape suspensory fixation system was rare, indicating that the postoperative result of AC stabilization is not categorically at risk when performing this procedure. Even though radiological assessment of the patients showed a statistically significant immediate superior clavicular displacement after this rarely required procedure, with an increased incidence in the first year following stabilization, this may not negatively influence the results of ACJ stabilization in a clinically relevant way. LEVEL OF EVIDENCE: IV.

Biomechanical comparison of lower trapezius and latissimus dorsi transfer for irreparable posterosuperior rotator cuff tears using a dynamic shoulder model.

BACKGROUND: In the setting of irreparable posterosuperior rotator cuff tears (PSRCTs), lower trapezius transfer (LTT) may be anatomically better positioned for restoring the muscular force couple compared with latissimus dorsi transfer (LDT). The purpose of the study was to evaluate the effect of LTT and LDT on glenohumeral kinematics using a dynamic shoulder model. METHODS: Ten fresh-frozen cadaveric shoulders (mean age: 56.5 ± 17.2 years) were tested using a dynamic shoulder simulator. The maximum abduction angle (MAA), superior humeral head migration (SHM), and cumulative deltoid forces (CDFs) were compared across 4 conditions: (1) native; (2) irreparable PSRCT; (3) LTT using an Achilles tendon allograft; and (4) LDT. MAA and SHM were measured using 3-dimensional motion tracking. CDF was recorded in real time throughout the dynamic abduction motion by load cells connected to actuators. RESULTS: Compared to the native state, the PSRCT resulted in a significant decrease (Δ-24.1°; P < .001) in MAA, with a subsequent significant increase after LTT (Δ13.1°; P < .001) and LDT (Δ8.9°; P < .001). LTT achieved a significantly greater MAA than LDT (Δ4.2°; P = .004). Regarding SHM, both LTT (Δ-9.4 mm; P < .001) and LDT (Δ-5.0 mm; P = .008) demonstrated a significant decrease compared with the PSRCT state. LTT also achieved significantly less SHM compared with the LDT (Δ-4.4 mm; P = .011). Further, only the LTT resulted in a significant decrease in CDF compared with the PSRCT state (Δ-21.3 N; P = .048), whereas LTT and LDT showed similar CDF (Δ-11.3 N; P = .346). However, no technique was able to restore the MAA, SHM, and CDF of the native shoulder (P < .001, respectively). CONCLUSION: LTT and LDT both achieved a significant increase in MAA along with significantly less SHM compared with the PSRCT state. Although LTT required significantly less compensatory deltoid forces compared with the PSRCT state, this was not observed for the LDT. Further, the LTT prevented loss of abduction motion and SHM more sufficiently. In the challenging treatment of irreparable PSRCTs, LTT may restore native glenohumeral kinematics more sufficiently, potentially leading to improved postoperative functional outcomes.

LUCL reconstruction of the elbow: clinical midterm results based on the underlying pathogenesis.

PURPOSE: Traumatic and atraumatic insufficiency of the lateral ulnar collateral ligament (LUCL) can cause posterolateral rotatory instability (PLRI) of the elbow. The influence of the underlying pathogenesis on functional outcomes remains unknown so far. The objective of this study was to determine the impact of the initial pathogenesis of PLRI on clinical outcomes after LUCL reconstruction using an ipsilateral triceps tendon autograft. METHODS: Thirty-six patients were reviewed in this retrospective study. Depending on the pathogenesis patients were assigned to either group EPI (atraumatic, secondary LUCL insufficiency due to chronic epicondylopathia) or group TRAUMA (traumatic LUCL lesion). Range-of-motion (ROM) and posterolateral joint stability were evaluated preoperatively and at follow-up survey. For clinical assessment, the Mayo elbow performance (MEPS) score was used. Patient-reported outcomes (PROs) consisting of visual analogue scale (VAS) for pain, disability of arm, shoulder and hand (DASH) score, patient-rated elbow evaluation (PREE) score and subjective elbow evaluation (SEV) as well as complications were analyzed. RESULTS: Thirty-one patients (group EPI, n = 17; group TRAUMA, n = 14), 13 men and 18 women with a mean age of 42.9 ± 11.0 were available for follow-up evaluation (57.7 ± 17.5 months). In 93.5%, posterolateral elbow stability was restored (n = 2 with re-instability, both group TRAUMA). No differences were seen between groups in relation to ROM. Even though group EPI (98.9 ± 3.7 points) showed better results than group TRAUMA (91.1 ± 12.6 points) (p = 0.034) according to MEPS, no differences were found for evaluated PROs (group A: VAS 1 ± 1.8, PREE 9.3 ± 15.7, DASH 7.7 ± 11.9, SEV 92.9 ± 8.3 vs. group B: VAS 1.9 ± 3.2, PREE 22.4 ± 26.1, DASH 16.0 ± 19.4, SEV 87.9 ± 15.4. 12.9% of patients required revision surgery. CONCLUSION: LUCL reconstruction using a triceps tendon autograft for the treatment of PLRI provides good to excellent clinical outcomes regardless of the underlying pathogenesis (traumatic vs. atraumatic). However, in the present case series, posterolateral re-instability tends to be higher for traumatic PLRI and patient-reported outcomes showed inferior results. LEVEL OF EVIDENCE: Therapeutic study, LEVEL III.

Biconcave glenoids show 3 differently oriented posterior erosion patterns.

BACKGROUND: Posterior glenoid wear remains a challenge in anatomic and reverse total shoulder arthroplasty (rTSA) because of an asymmetric erosion with altered retroversion. The purpose of this study was to assess glenoid morphology and evaluate the influence of acromial orientation in posterior glenoid erosion patterns by using 3-dimensional (3D) models. MATERIAL AND METHODS: Computed tomographic (CT) shoulder scans from 3 study centers of patients awaiting rTSA between 2017 and 2018 were converted into 3D models and analyzed by 2 observers. Morphology, orientation and greatest depth of erosion, inclination, current retroversion and premorbid retroversion, surface areas of the glenoid, and external acromial orientation and posterior acromial slope were assessed. Measurements were compared between wear patterns, glenoid erosion entities, and genders. RESULTS: In the complete cohort of 68 patients (63.8 ± 10.0 years; 19 female, 49 male), a mean of 85.9° (±22.2°) was observed for the glenoid erosion orientation. Additionally, a further distinct classification of the glenoid erosion as posterior-central (PC, n = 39), posterior-inferior (PI, n = 12), and posterior-superior (PS, n = 17) wear patterns was possible. These wear patterns significantly (P < .001) distinguished by erosion orientation (PC = 86.9° ± 12.0°, PI = 116.3° ± 10.3°, PS = 62.3° ± 18.9°). The greatest depth of erosion found was 7.3 ± 2.7 mm in PC wear patterns (PC vs. PI: P = .03; PC vs. PS: n.s.; PI vs. PS: n.s.). Overall, the observed erosion divided the glenoid surface into a paleoglenoid proportion of 48% (±11%) and a neoglenoid proportion of 52% (±12%). For the complete cohort, glenoid inclination was 85.4° (±6.6°), premorbid glenoid retroversion was 80.7° (±8.1°), and current glenoid retroversion was 73.4° (±7.4°), with an estimated increase of 6.9° (±6.0°). The mean external acromial orientation was 118.2° (±8.9°), and the mean posterior acromial slope was 107.2° (±9.6°). There were no further significant differences if parameters were compared by wear patterns, entities, and gender. CONCLUSION: Three significantly differently oriented wear patterns (posterior-superior, posterior-central, and posterior-inferior) were distinguished in shoulders demonstrating posterior wear on axillary imaging. No significant differences between the observed erosion patterns or any relevant correlations were found regarding the orientation of the acromion.

Indications for Arthroscopic Subacromial Decompression. A Level V Evidence Clinical Guideline.

Since the introduction of acromioplasty by Neer in 1971 and arthroscopic subacromial decompression (SAD) by Ellman in 1987, the outcomes have been reported to be consistently good. Recently it was suggested that supervised physical therapy is comparable with SAD, which was contested by other studies claiming that SAD is clearly superior to nonoperative treatment. Before consideration for treatment, the diagnosis of impingement with an intact rotator cuff must be determined by clinical history, a detailed and structured clinical examination, and appropriate imaging. In favor of SAD are published long-term studies with a minimum of 10 years outlining significant functional and clinical improvement. The main factor for failure reported was workers compensation, calcific tendinopathy, and high-grade partial-thickness tears. Studies nonsupportive of SAD suffer from bias, crossover from the nonoperative group to the operative group following failure of conservative treatment, and loss of follow-up. Recently, lateral acromion resection has been suggested as a viable alternative, effectively reducing the critical shoulder angle. Following nonoperative treatment for at least 6 weeks, SAD is a viable and good surgical option for the treatment of shoulder impingement with an intact rotator cuff. Care should be taken to avoid resection of the acromioclavicular ligament. Five millimeters of lateral acromion resection is the recommended amount of resection. Patients with chronic calcific tendinitis, workers compensation, and partial-thickness tears should not be treated by SAD alone.

Reconstruction of the Acromioclavicular Ligament Complex Using Dermal Allograft: A Biomechanical Analysis.

PURPOSE: To analyze the posterior translational and rotational stability of the acromioclavicular (AC) joint following reconstruction of the superior acromioclavicular ligament complex (ACLC) using dermal allograft. METHODS: Six fresh-frozen cadaveric shoulders were used (mean age of 65.3 ± 6.9 years). The resistance force against posterior translation (10 mm) and torque against posterior rotation (20°) was measured. Specimens were first tested with both the intact ACLC and coracoclavicular ligaments. The ACLC and coracoclavicular ligaments were then transected so simulate a Type III/V AC joint dislocation. Each specimen then underwent 3 testing conditions, performed in the following order: (1) ACLC patch reconstruction alone, (2) ACLC patch with an anatomic coracoclavicular reconstruction (ACCR) using semitendinosus allograft, and (3) the transected ACLC with an ACCR only. Differences in posterior translational and rotational torque across testing conditions were analyzed with a one-way repeated analysis of variance analysis. RESULTS: Mean resistance against posterior translation in the intact condition was 65.76 ± 23.8 N. No significant difference found between the intact condition compared with specimens with the ACLC-patch only (44.2 ± 11.3 N, P = .06). The ACCR technique, when tested alone, had significantly less posterior translational resistance compared with the intact condition (38.5 ± 8.94 N, P = .008). ACLC patch in combination with an ACCR was closest in restoring native posterior translation (57.1 ± 19.2 N, P = .75). For rotational resistance, only the addition of the ACLC patch with an ACCR (0.51 ± 0.07 N-m) demonstrated similar torque compared with the intact joint (0.89 ± 0.5 N-m, P = .06). CONCLUSIONS: The ACLC-patch plus ACCR technique was able to closest restore the percent of normal posterior translational and rotational stability. CLINICAL RELEVANCE: Recurrent posterior instability of the AC joint is a potential complication after coracoclavicular reconstruction surgery. In the in vitro setting, this study demonstrated increased AC joint stability with the addition of an ACLC reconstruction using dermal allograft.

The Effect of Glenohumeral Fixation Angle on Deltoid Function During Superior Capsule Reconstruction: A Biomechanical Investigation.

PURPOSE: To evaluate the effect of dermal allograft fixation at different angles of glenohumeral abduction on deltoid forces during superior capsule reconstruction (SCR). METHODS: Fifteen cadaveric specimens were tested using a dynamic shoulder simulator. Following testing in the native state, shoulders underwent SCR in 2 of 5 possible fixation angles; 0°, 15°, 30°, 45°, or 60° of glenohumeral abduction, allowing for 6 specimens per group. Angles were measured radiographically with the glenoid fixed perpendicular to the floor. Maximum mean deltoid abduction force was compared among 5 separate conditions within each angle group: (1) native shoulder, (2) complete supraspinatus (SSP) and superior capsule tear, (3) SCR alone, (4) SCR with posterior margin sutured, and (5) SCR with anterior and posterior margins sutured. RESULTS: SSP tears significantly increased the maximum deltoid forces for all 5 fixation angles compared with the native state (P < .05). Specimens repaired at 0°, 30°, and 45° were unable to restore deltoid forces compared with the native state in any condition (P < .05). SCR at 15° with anterior and posterior margin convergence showed similar abduction forces compared with the native state (P = .19). When fixed at 60° abduction, SCR alone significantly reduced deltoid forces compared to SSP (Δ143N, P < .001) and native (Δ48N, P < .001). No significant differences were found between the 3 repair subtypes (SCR ± anterior/posterior margin repair) in the 60° group. CONCLUSIONS: SCR with anterior and posterior margin convergence tensioned at 15° of glenohumeral abduction showed similar deltoid abduction force requirements compared with the native state, whereas graft fixation in 60° significantly reduced deltoid force in all SCR conditions. CLINICAL RELEVANCE: Increased graft tension with a greater abduction angle may provide greater functional outcome by placing less load on the deltoid. In contrast, graft fixation in lower abduction angles may require additional margin convergence to reproduce native forces.

Biomechanical Effect of Superior Capsule Reconstruction Using a 3-mm and 6-mm Thick Acellular Dermal Allograft in a Dynamic Shoulder Model.

PURPOSE: To biomechanically compare the effect of superior capsule reconstruction (SCR) using a 3- and 6-mm thick acellular dermal allograft for the treatment of irreparable rotator cuff tears. METHODS: Eight fresh-frozen cadaveric shoulders were tested using a dynamic shoulder model. Maximum abduction angle (MAA), glenohumeral superior translation (ghST), subacromial peak contact pressure (sPCP), and cumulative deltoid force (cDF) were compared among 4 conditions: (1) intact shoulder, (2) simulated irreparable rotator cuff tear (RCT), (3) SCR using a 3-mm-thick acellular dermal allograft, (4) SCR using a 6-mm-thick acellular dermal allograft. RESULTS: Compared with the intact state, simulated irreparable RCTs significantly decreased MAA (P < .001), while significantly increasing ghST (P = .001), sPCP (P < .001), and cDF (P < .001). SCR with a 3-mm-thick graft significantly increased MAA (P = .01) and decreased ghST (P = .01) compared with the RCT state, however, showed similar sPCP and cDF. Compared with the torn state, SCR with a 6-mm-thick graft significantly increased MAA (P < .001) and significantly decreased ghST (P < .001), sPCP (P < .001), and cDF (P = .001). Using a 6-mm-thick graft demonstrated similar MAA, ghST, sPCP, and cDF compared with the intact state. When comparing the 3-mm to the 6-mm thick graft, significant differences were found in ghST (P = .03), sPCP (P < .001), and cDF (P = .02). CONCLUSIONS: SCR with a 6-mm-thick acellular dermal allograft better restored normal glenohumeral joint position and forces compared with a 3-mm-thick graft for the treatment of irreparable RCTs. CLINICAL RELEVANCE: Graft thickness may affect the clinical success following SCR with commercially available dermal allografts. Using a thicker (>3 mm) graft was able to biomechanically better restore native glenohumeral joint properties.

LUCL internal bracing restores posterolateral rotatory stability of the elbow.

PURPOSE: Posterolateral rotatory instability (PLRI) of the elbow occurs from an insufficient lateral collateral ligament complex (LCLC). For subacute LCLC injuries, lateral ulnar collateral ligament (LUCL) internal bracing rather than reconstruction may be a viable option. The purpose of the study was to compare the stabilizing effects of LUCL internal bracing to triceps tendon graft reconstruction in simulated PLRI. METHODS: Sixteen cadaveric elbows were assigned for either LUCL internal bracing (n = 8) or reconstruction with triceps tendon graft (n = 8). Specimen were mounted and a valgus rotational torque was applied to the ulna to test posterolateral rotatory stability. Posterolateral rotation was measured at 0°, 30°, 60°, 90° and 120° of elbow flexion. Cyclic loading was performed for 1000 cycles at 90° of elbow flexion. Three conditions were compared in each specimen: intact elbow, LUCL and radial collateral ligament (RCL) transected, and then either LUCL internal bracing or reconstruction with triceps tendon graft. RESULTS: Transection of the LUCL and RCL significantly increased posterolateral rotation in all degrees of elbow flexion compared to the intact condition (P < 0.05). Both LUCL internal bracing and reconstruction restored posterolateral rotatory stability to the native state between 0° and 120° of elbow flexion, with no significant difference in improvement between groups. Similarly, LUCL internal bracing and reconstruction groups showed no significant difference in posterolateral rotation compared to the intact condition during cyclic loading. CONCLUSIONS: At time zero, both LUCL internal bracing and reconstruction with triceps tendon graft restored posterolateral rotatory stability. As such, this study supports the use of internal bracing as an adjunct to primary ligament repair in subacute PLRI.

Repair of the entire superior acromioclavicular ligament complex best restores posterior translation and rotational stability.

PURPOSE: The acromioclavicular ligament complex (ACLC) is the primary stabilizer against horizontal translation with the superior ACLC providing the main contribution. The purpose of this study was to evaluate the specific regional contributions in the superior half of ACLC, where the surgeon can easily access and repair or reconstruct, for posterior translational and rotational stability. METHODS: The superior half of ACLC was divided into three regions; Region A (0°-60°): an anterior 1/3 region of the superior half of ACLC, Region B (60°-120°): a superior 1/3 region of the superior half of ACLC, and Region C (120°-180°): a posterior 1/3 region of the superior half of ACLC. Fifteen fresh-frozen cadaveric shoulders were used. Biomechanical testing was performed to evaluate the resistance force against passive posterior translation (10 mm) and the resistance torque against passive posterior rotation (20°) during the following the four conditions. (1) Stability was tested on all specimens in their intact condition (n = 15). (2) The ACLC was dissected and stability was tested (n = 15). (3) Specimens were randomly divided into three groups by regions of suturing. Stability was tested after suturing Region A, Region B, or Region C (n = 5 per group). (4) Stability was tested after suturing additional regions: Region A + B (0°-120°), Region B + C (60°-180°), or Region A + C (0°-60°, 120°-180°, n = 5 per group). RESULTS: The translational force increased after suturing Region A when compared with dissected ACLC (P = 0.025). The force after suturing Region A + B was significantly higher compared to the dissected ACLC (P < 0.001). The rotational torque increased after suturing Region A or Region B compared with dissected ACLC (P = 0.020, P = 0.045, respectively). The torque after suturing the Region A + C was significantly higher compared to the dissected ACLC (P < 0.001). CONCLUSION: The combined Region A + B contributed more to posterior translational stability than Region B + C or Region A + C. In contrast, combined Region A + C contributed more to posterior rotational stability than Region A + B or Region B + C. Based on these findings, surgical techniques restoring the entire superior ACLC are recommended to address both posterior translational and rotational stability of the AC joint.

Does quality of life influence retear rate following arthroscopic rotator cuff repair?

BACKGROUND: The primary objective was to assess whether a patient's early postoperative quality of life (QOL) correlates with the retear rate following single-tendon double-row rotator cuff repair. METHODS: We performed a secondary analysis of a randomized clinical trial of 58 patients who underwent single-tendon arthroscopic rotator cuff repair of full-thickness tears performed by a single surgeon. Patients were randomized to an early- or delayed-motion protocol. At 6 months, all patients underwent magnetic resonance imaging to assess whether the rotator cuffs were intact or retorn. QOL was assessed preoperatively and at 3 weeks, 6 weeks, 12 weeks, 6 months, and 12 months postoperatively using the Western Ontario Rotator Cuff (WORC) index. RESULTS: After 6 months of rehabilitation, 41 patients (71%) had intact rotator cuff repairs whereas 17 (29%) had full-thickness tears. Patients with torn rotator cuffs at 6 months postoperatively had significantly lower WORC scores at 6 weeks postoperatively (P = .041). Patients with greater improvements in QOL perioperatively (preoperative WORC score minus 6-week postoperative WORC score > 264.5) were more likely to have full-thickness tears by 6 months postoperatively. Compliant patients assigned to the delayed-motion protocol had a failure rate of 11% (2 of 19) compared with 38% (15 of 39) in the noncompliant and early-motion protocol patients (P < .01). Overall, patients who were noncompliant with the shoulder immobilizer were 8.2 times more likely to have a failed repair on magnetic resonance imaging (P = .01). CONCLUSIONS: Patients with better QOL shortly after arthroscopic rotator cuff repair were more likely to have retears by 6 months.

[Operative treatment of stiff shoulder : Arthroscopic arthrolysis, mobilization under anesthesia and postoperative management]. / Operative Therapie der "stiff shoulder" : Arthroskopische Arthrolyse, Narkosemobilisation und postoperatives Management.

The operative treatment of stiff shoulder using arthroscopically assisted arthrolysis is indicated in patients with persistent, symptomatic and therapy-resistant movement restrictions. Patients should be informed about relevant risks, supervised rehabilitation and possible recurrences. The surgical procedure provides a precise and controlled semicircular capsulotomy and is followed by an intensive rehabilitation program in order to minimize the risk of recurrences.

Single cut distal femoral osteotomy for correction of femoral torsion and valgus malformity in patellofemoral malalignment - proof of application of new trigonometrical calculations and 3D-printed cutting guides.

BACKGROUND: The purpose of this study was to perform a derotational osteotomy at the distal femur, as is done in cases of patellofemoral instability, and demonstrate the predictability of three-dimensional (3D) changes on axes in a cadaveric model by the use of a new mathematical approach. METHODS: Ten human cadaveric femurs, with increased antetorsion, underwent a visually observed derotational osteotomy at the distal femur by 20°, as is commonly done in clinics. For surgery, a single cut osteotomy with a defined cutting angle was calculated and given using a simple 3D-printed cutting guide per specimen, based on a newly-created trigonometrical model. To simulate post-operative straight frontal alignment in a normal range, a goal for the mechanical lateral distal femur angle (mLDFA) was set to 87.0° for five specimens (87-goal group) and 90.0° for five specimens (90-goal group). Specimens underwent pre- and post-operative radiographic analysis with CT scan for torsion and frontal plane x-ray for alignment measurements of mLDFA and anatomical mechanical angle (AMA). RESULTS: Performed derotation showed a mean of 19.69° ±1.08°SD (95% CI: 18.91° to 20.47°). Regarding frontal alignment, a mean mLDFA of 86.9° ±0.66°SD (87-goal-group) and 90.42° ±0.25° SD (90-goal group), was observed (p = 0.008). Overall, the mean difference between intended mLDFA-goal and post-operatively achieved mLDFA was 0.14° ±0.56° SD (95% CI: -0.26° to 0.54°). CONCLUSION: A preoperative calculated angle for single cut derotational osteotomy at the distal femur leads to a clinically precise post-operative result on torsion and frontal alignment when using this approach.

Higher Critical Shoulder Angle and Acromion Index Are Associated With Increased Retear Risk After Isolated Supraspinatus Tendon Repair at Short-Term Follow Up.

PURPOSE: To evaluate the effect of critical shoulder angle (CSA), acromion index (AI), and glenoid inclination (GI) on the postoperative healing rate after arthroscopic supraspinatus tendon repair. METHODS: Patients after arthroscopic repair of a symptomatic, unilateral, single-tendon, full-thickness supraspinatus tear in whom nonoperative management had failed were retrospectively reviewed. Magnetic resonance imaging (MRI) studies were obtained 6 months postoperatively and were evaluated by 2 independent observers. Repair integrity was classified as either intact or torn. Preoperative true anteroposterior radiographs were used to measure CSA, AI, and GI. RESULTS: Fifty-seven patients were evaluated 6 months postoperatively. The mean patient age at surgery was 54.7 ± 7.7 years. On MRI studies, 41 patients (71.9%) had an intact repair and 16 patients (28.1%) had a full-thickness retear. There were no significant differences between the intact and retear group in regard to patient age (P = .648), initial tear size (P = .205), or fatty degeneration (P = .508). The mean CSA for the retear group (37° ± 4°) was significantly higher than that in the intact group (35° ± 3°; P = .014). If the CSA was >38°, the odds ratio of having a retear was 3.78 (95% confidence interval 1.05 to 13.58; P = .042). Average AI for the retear group (0.73 ± 0.09) was significantly higher than that in the intact group (0.69 ± 0.06; P = .049). The mean GI was 17° ± 6° for the intact group and 16° ± 6° for the retear group (P = .739). CONCLUSIONS: At short-term follow-up, higher CSA and AI significantly increased the retear risk after arthroscopic supraspinatus tendon repair. CSA >38° increased the retear risk almost 4-fold. Overall GI was elevated but did not correlate with failure rate. LEVEL OF EVIDENCE: III, case control study.