Complications Within 6 Months After Arthroscopic Rotator Cuff Repair: Registry-Based Evaluation According to a Core Event Set and Severity Grading.

PURPOSE: To report complications after arthroscopic rotator cuff repairs (ARCRs) in a large patient cohort based on clinical application of a newly defined core event set (CES) and severity grading. METHODS: Consecutive primary ARCRs documented in a local clinical registry between February 2010 and September 2016 were included. Clinicians documented adverse events (AEs) reported until the final, 6-month postoperative follow-up according to the CES. The CES is an organized list of relevant AEs sorted into 3 intraoperative event groups (device, osteochondral, and soft tissue) and 9 postoperative event groups (device, osteochondral, pain, rotator cuff, surgical-site infection, peripheral neurologic, vascular, superficial soft tissue, and deep soft tissue). Severity was determined using an adaptation of the Clavien-Dindo classification. Cumulative complication risks were calculated per event group and stratified by severity and rotator cuff tear extent. RESULTS: A total of 1,661 repairs were documented in 1,594 patients (mean age, 57 years [standard deviation, 9 years]; 38% women); 21% involved partial tears. All events were recorded according to the CES. Intraoperative events occurred in 2.2% of repairs. We identified 329 postoperative events in 307 repairs (305 patients); 93% had 1 AE. The cumulative AE risk at 6 months was 18.5%; AE risks were 21.8% for partial tears, 15.8% for full-thickness single-tendon tears, 18.0% for tears with 2 ruptured tendons, and 25.6% for tears with 3 ruptured tendons. AE risks per event group were as follows: 9.4% for deep soft tissue, with shoulder stiffness (7.6%) being the most common event; 3.4% for persistent or worsening pain; 3.1% for rotator cuff defects; 1.7% for neurologic lesions; 0.8% for surgical-site infection; 0.7% for device; 0.4% for osteochondral; 0.2% for superficial soft tissue, and 0.1% for vascular. Most AEs had severity grades I (160 [49%]) and II (117 [36%]). CONCLUSIONS: Comprehensive local AE documentation according to the CES and severity grading was possible and showed that about one-fifth of ARCRs were affected, mostly by one AE of low severity. Shoulder stiffness was the most frequent event. LEVEL OF EVIDENCE: Level IV, case series.

Short-term safety, function, and quality of life in patients treated with Univers Revers prosthesis: a multicenter 2-year follow-up case series.

BACKGROUND: The use of reverse total shoulder arthroplasty (RTSA) has dramatically increased in recent years with the advent of new prosthesis designs regularly entering the market. We define the rate of local complications during the first 2 years after RTSA with the Univers Revers prosthesis and describe the changes in radiologic outcomes, as well as function, pain, satisfaction, and quality of life. METHODS: This multicenter, prospective case series included rotator cuff tear arthropathy patients who underwent RTSA with the Univers Revers. Incidence percentages of complications and pathologic radiographic changes were documented. Mixed-model linear regression was used to examine changes in range of motion, shoulder function (Constant score, Shoulder Pain and Disability Index, Subjective Shoulder Value), and quality of life (EQ-5D-5L [European Quality of Life 5 Dimensions 5 Level] and EQ-VAS [EuroQol Visual Analog Scale]). RESULTS: Of 187 patients, 59.4% were women, and the mean age was 75.3 years (range, 56-91 years). Twenty-five percent of patients had a postoperative complication; 5 complications were severe (2.7%, 5 of 187), whereby 2 were implant related (1.1%; 95% confidence interval [CI], 0.1%-3.8%). The incidence of scapular notching was 10.6% (95% CI, 6.5%-16%). After 2 years, abduction, flexion, and abduction strength improved by 54° (95% CI, 50°-58°), 57° (95% CI, 53°-60°), and 5 kg (95% CI, 4-5 kg), respectively (P < .001), whereas external rotation at 0° (1°; 95% CI, -1° to 3°) did not improve (P = .4). The Constant score improved by 39 (95% CI, 38-41); Shoulder Pain and Disability Index, by 50 (95% CI, 47-52); and Subjective Shoulder Value, by 43 (95% CI, 41-45) (P < .001). Furthermore, the EQ-5D-5L index value improved by 0.31 (95% CI, 0.30-0.33), and the EQ-VAS score improved by 16 (95% CI, 14-18) (P < .001). CONCLUSION: Our case series showed a low complication rate with a consistent clinically relevant and statistically significant improvement across most clinical and patient-reported outcomes for the Univers Revers. Long-term safety requires further investigation.

Repair of Lafosse I subscapularis lesions brings no benefit in anterosuperior rotator cuff reconstruction.

PURPOSE: Optimal management of partial anterosuperior rotator cuff tears is unknown. Our aim was to compare clinical and subjective outcomes of supraspinatus (SSP) repair patients treated with or without repair of an associated superior subscapularis (SSC) partial tear. METHODS: SSP repair patients with an associated partial (Lafosse I) tear of the superior SSC tendon were retrospectively examined. Baseline and operative data and the outcomes of shoulder range of motion (ROM), pain level, strength, Constant-Murley Score, complications at 6 months as well as patient-reported Oxford Shoulder Score, Subjective Shoulder Value, and satisfaction at 6- and 24-month post-surgery were compared between patients with and without a repaired SSC tear. Mixed models and propensity-score matching were used to adjust baseline group differences. RESULTS: Of 75 eligible patients, 34 had an SSC repair and were younger with better baseline function. Non-repair surgeries were significantly shorter by 34 min (95% CI 23-45; p < 0.001). There were no group differences in the clinical and patient-rated outcome scores at both follow-ups (n.s.) as well as in pain, muscle strength in abduction, ROM, the 6-month complication risk (risk difference - 1.9%), and satisfaction with postoperative shoulder condition (n.s.). CONCLUSION: We could not show a functional or subjective benefit of repairing cranial partial tears of the SSC tendon over debridement only in the setting of an SSP reconstruction with 24 months of follow-up. A longer operative duration is expected if a partial SSC tear repair is performed. LEVEL OF EVIDENCE: III.

Latissimus dorsi muscle transfer reduces external rotation deficit at the cost of internal rotation in reverse shoulder arthroplasty patients: a cohort study.

HYPOTHESIS: We hypothesized that treatment of rotator cuff arthropathy (RCA) with reverse shoulder arthroplasty (RSA) and an additional latissimus dorsi transfer (LDT) in patients with an active external rotation deficit (ERD) would restore external rotation (ER) with concomitant deterioration in internal rotation. METHODS: In our cohort study, 26 RCA patients with an active ERD (ie, positive lag sign and maximum active ER of 0°) underwent RSA between September 2007 and February 2015; LDT was completed in 13 of these patients. In addition, 88 control patients without ERD who underwent only RSA were identified. Clinical outcomes of strength, range of motion, Constant-Murley score, and Shoulder Pain and Disability Index score, as well as complications, were documented 6, 12, 24, and 60 months postoperatively. We made comparative analyses using statistical mixed models. RESULTS: The LDT procedure extended the surgical time by 26 minutes (P = .003). LDT patients had up to 22° better postoperative active ER than control patients (P < .001), although this was accompanied by an internal rotation deficit (77% vs 46% of control patients could not reach the lumbosacral region, P = .010). We calculated a 23% risk of local procedure-related complications for RSA patients with an active ERD and LDT. CONCLUSION: Patients with RCA and an active ERD seem to benefit from an LDT, although this is accompanied by the potential loss of internal rotation. This additional procedure is associated with an extended surgical time as well as a possible increase in the risk of a complication occurring.

Functional improvement is sustained following anatomical and reverse shoulder arthroplasty for fracture sequelae: a registry-based analysis.

INTRODUCTION: Shoulder arthroplasty for proximal humerus fracture sequelae is known to provide significant patient improvement, yet this outcome varies with time, prosthesis type, and fracture sequelae. We outline the expected course of postoperative shoulder pain and function in patients with anatomical (ASA) or reverse (RSA) shoulder arthroplasty following different fracture sequelae. MATERIALS AND METHODS: Of 111 consecutive patients from our local shoulder arthroplasty registry, 32 underwent ASA for Boileau type 1 sequelae and 77 RSA patients were identified with Boileau types I, III, and IV. By 5 year post-surgery, there were 72 patients available. All patients underwent standardised ASA or RSA procedures with anatomical (Promos Standard; Lima SMR™; Arthrex Eclipse™; Univers™ II) or reverse prostheses (Promos Reverse®; Lima SMR™ Reverse; Univers Revers™; Aequalis® Reversed). Range of motion, Constant-Murley, Disability of the Arm, Shoulder and Hand (DASH), and Shoulder Pain and Disability Index (SPADI) scores were compared at 6, 12, 24, and 60 months postoperatively. We used generalised linear mixed models or random-effects ordered logistic regression to investigate postoperative changes of outcome parameters from baseline to follow-up time points for each group as well as for group comparisons. RESULTS: Range of motion and clinical scores improved until 24 months postoperatively and did not deteriorate thereafter, except for internal rotation of Boileau type III and IV patients and external rotation of RSA patients with type I and IV sequelae. At all follow-ups, ASA patients with Boileau type I sequelae had significantly better internal and external rotation versus patients with RSA and/or other Boileau types (p < 0.001), while Constant, DASH, and SPADI scores were not significantly different between groups. CONCLUSION: In humeral fracture sequelae, ASA and RSA lead to sustained clinical improvements. Surgeons may primarily consider implantation of ASA in type I sequelae.

Porcine Dermis Patch Augmentation of Supraspinatus Tendon Repairs: A Pilot Study Assessing Tendon Integrity and Shoulder Function 2 Years After Arthroscopic Repair in Patients Aged 60 Years or Older.

PURPOSE: To investigate the 2-year postoperative clinical and subjective outcomes after arthroscopic rotator cuff repair (ARCR) with xenologous porcine dermal patch augmentation compared with ARCR alone. METHODS: Patients aged 60 years or older with a complete supraspinatus (SSP) tendon tear underwent primary ARCR with a transosseous-equivalent technique. By use of a matched-pair comparative trial design, a consecutive series of 20 patients receiving additional xenologous porcine dermal patch augmentation (patch group) was matched by tear location with 20 patients who received ARCR only (control group). Prior conservative treatment failed in all patients. Patients with concomitant pathologies precluding accurate repair assessment, partial or open reconstruction, or a latissimus dorsi and/or pectoralis major muscle transfer were excluded. Patients reported daily pain levels for 10 days after surgery. Clinical parameters and various patient-reported outcome scores were documented preoperatively and at 3, 6, and 24 months after surgery. Repair integrity was determined by magnetic resonance imaging or ultrasound at 24 months. Adverse events were recorded. Group outcome differences were analyzed with t tests, Fisher exact tests, and mixed models. RESULTS: Patients in both groups were aged 67 years on average (range, 60-74 years), and 70% of patients were men. Patients in the patch group had slightly more SSP fatty infiltration preoperatively. Patch surgical procedures were on average 22 minutes longer than control interventions (P = .003). At 24 months, 4 patients and 9 patients were diagnosed with a recurrent SSP tendon defect in the control group (n = 20) and patch group (n = 19), respectively (relative risk, 2.4; P = .096). Of 11 defects (85%) identified as medial cuff failure, 8 occurred in the patch group. Pain rated by all patients decreased from postoperative day 1 to day 10 without any significant group difference (P = .348). No significant group differences were noted for other outcome parameters, and recurrent defects had no relevant effect on functional outcomes. Local complications (including recurrent defects) occurred in 8 patients in the control group and 12 in the patch group (P = .343). CONCLUSIONS: Our pilot study supports the view that an SSP tear repair with porcine dermal xenograft augmentation does not benefit patients in terms of reducing the risk of a recurrent tendon defect or improving shoulder function up to 24 months after surgical repair. LEVEL OF EVIDENCE: Level III, therapeutic study, retrospective comparative trial.

Glenosphere size in reverse shoulder arthroplasty: is larger better for external rotation and abduction strength?

BACKGROUND: The role of glenosphere size in reverse shoulder arthroplasty (RSA) may be important in prosthetic stability, joint kinematics, rotator cuff tension and excursion, scapular impingement, humeral lateralization, deltoid wrap, and the occurrence of "notching." This study compared short- and midterm clinical and radiographic outcomes for 2 different glenosphere sizes of a single RSA type with respect to implant positioning, glenoid size, and morphology. METHODS: This retrospective analysis included 68 RSA procedures that were prospectively documented in a local register during a 5-year postoperative period. Two glenosphere diameter sizes of 36 mm (n = 33) and 44 mm (n = 35) were used. Standard radiographs were made preoperatively (ie, baseline) and at 6, 12, 24, and 60 months after surgery. Range of motion, strength, the Constant-Murley score, and the Shoulder Pain and Disability Index were also assessed at all follow-up visits. The effect of glenosphere size on measured outcomes was adjusted for baseline values, patient gender, and humeral head diameter. RESULTS: No significant differences were found in the functional scores between treatment groups at all follow-up assessments. At the 12-month follow-up, patients with a 44-mm glenosphere had greater external rotation in adduction (mean difference, 12°; P = .001) and abduction strength (mean difference, 1.4 kg; P = .026) compared with those with the smaller implant. These differences remained at 60 months. Scapular notching was observed in 38% of all patients, without any relevant difference between the groups. CONCLUSION: An increase in glenosphere diameter leads to a clinically moderate but significant increase in external rotation in adduction and abduction strength at midterm follow-up.

Influence of patient and diagnostic parameters on reported retear rates after arthroscopic rotator cuff repair.

PURPOSE: The purpose of this meta-analysis was to investigate patient and diagnostic parameters influencing the reported rates of recurrent rotator cuff defects after ARCR. METHODS: PubMed, EMBASE, Cochrane Library and Scopus databases were searched for clinical studies on tendon defects after ARCR. Imaging modalities, definitions, detection time points, and other known patient risk factors (patient age, tear severity, grade of fatty infiltration, repair technique) as well as reported defect rates were extracted. A meta-analysis of proportion and meta-regression analysis were used to investigate independent variables influencing reported defect rates. RESULTS: Of 109 articles reviewed, the diagnostic studies used magnetic resonance imaging (MRI) only (n = 56), ultrasound (US) only (n = 28), MRI or computed tomography (CT) arthrography (CTA, n = 14) or a combination of US, MRI and CTA (n = 11) up to 57 months after ARCR. Definitions of tendon defects were highly variable, including those of partial tendon healing with insufficient thickness defined as either an acceptable outcome (n = 72) or a recurrent defect (n = 22). Reported defect rates demonstrated highly significant heterogeneity between studies and groups. Follow-up time and the evaluation of partial tendon healing were independent factors of the defect rate alongside age, tear severity and repair technique. The type of imaging did not significantly alter defect rates. CONCLUSION: A number of specific factors significantly alter the rates of rotator cuff defects reported after ARCR. Standardized protocols in clinical practice are required for consistent diagnosis of recurrent defects after ARCR. LEVEL OF EVIDENCE: IV.

Radiological and functional 24-month outcomes of resurfacing versus stemmed anatomic total shoulder arthroplasty.

PURPOSE: This study compared clinical and radiographic outcomes of patients undergoing resurfacing total shoulder arthroplasty (TSA) with those treated with a stemmed TSA. METHODS: Patients with primary osteoarthritis who underwent humeral resurfacing (RES) or stemmed (STA) TSA were identified in our shoulder arthroplasty register for retrospective analysis. Standard radiographs and clinical/patient-rated assessments were made up to 24 months post-surgery. Implant revisions were assessed. Patients were frequency-matched in a 1:1 (RES:STA) ratio based on gender and age, and compared with regard to operation time and shoulder function (Constant, SPADI and Quick DASH scores). Mixed models with statistical adjustments were applied. RESULTS: From 2006 to 2014, 44 RES and 137 STA operations were performed in 157 patients; one and two revisions were recorded in the RES and STA group, respectively. The final matched cohort included a total of 69 patients and 37 operations per treatment group. Resurfacing TSA was 17 min shorter (95%CI: 5-28) compared to the stemmed procedure (p = 0.005). RES and STA patients showed significant functional improvement six months post-implantation, yet all measured scores did not differ between the groups at 2 years (p ≥ 0.131). The status of static centering of the humeral head, acromiohumeral distance, and a lack of signs of implant loosening were also similar between treatments. CONCLUSION: Similar 24-month post-operative radiological and functional outcome is achieved by RES and STA patients, even with a shorter RES surgery time. Larger cohorts and longer follow-up are required to better assess implant survival.

Towards standardised definitions of shoulder arthroplasty complications: a systematic review of terms and definitions.

INTRODUCTION: A transparent, reliable and accurate reporting of complications is essential for an evidence-based evaluation of shoulder arthroplasty (SA). We systematically reviewed the literature for terms and definitions related to negative events associated with SA. MATERIALS AND METHODS: Various biomedical databases were searched for reviews, clinical studies and case reports of complications associated with SA. Any general definition of a complication, classification system, all reported terms related to complications and negative events with their definitions were extracted. Terms were grouped and organised in a hierarchical structure. Definitions of negative events were tabulated and compared. RESULTS: From 1086 initial references published between 2010 and 2014, 495 full-text papers were reviewed. Five reports provided a general definition of the term "surgical complication" and 29 used a classification system of complications. A total of 1399 extracted terms were grouped based on similarities and involved implant or anatomical parts. One hundred and six reports (21.4%) defined at least one negative event for 28 different terms. There were 64 definitions related to humeral or glenoid loosening, and 25 systems documenting periprosthetic radiolucency. Other definitions considered notching, stress shielding, implant failure and tuberosity malposition. CONCLUSIONS: A clear standardised set of SA complication definitions is lacking. Few authors reported complications based on definitions mainly considering radiological criteria without clinical parameters. This review should initiate and support the development of a standardised SA complication core set.

Arthroscopic treatment of anterior shoulder instability associated with a HAGL lesion-a case series.

BACKGROUND: Restoration of shoulder stability after humeral avulsion of glenohumeral ligament (HAGL) lesions can be achieved with arthroscopy, yet limited evidence exists on its benefit. We evaluated objective and subjective outcomes after arthroscopic refixation of a HAGL lesion. METHODS: Between 2009 and 2012, 8 patients were treated arthroscopically for anterior shoulder instability associated with a HAGL lesion and invited for a follow-up examination. Radiographic assessment of joint centering and osteoarthritis, clinical assessment including Constant and Rowe scores, and complications as well as functional outcomes using the Western Ontario Shoulder Instability Index, Subjective Shoulder Value, and Simple Shoulder Test were documented. RESULTS: Six patients were postoperatively examined at a median time of 29 months (range, 12-38). Four patients had up to 6 previous luxation events. Two patients had a concomitant labral lesion, and another 2 had an associated rotator cuff tear. Positive preoperative apprehension and relocation test results for 5 patients were negative at follow-up. No neurologic lesion was noted both before and after surgery. Shoulder motion did not improve significantly; lower internal and external rotation relative to the contralateral shoulder was reported. The Rowe score improved significantly from baseline (median score change, 65 points; P = .027), with 2 and 4 patients rating "good" and "excellent" at follow-up, respectively. Final median Constant score, Western Ontario Shoulder Instability Index, Subjective Shoulder Value, and Simple Shoulder Test scores were 77.3 points, 91.0 points, 90%, and 87.5 points, respectively. CONCLUSION: Arthroscopic stabilization of a HAGL lesion is a safe, feasible, and reproducible technique. In our patient cohort, good shoulder stability could be achieved with high patient satisfaction.

Complications associated with arthroscopic rotator cuff tear repair: definition of a core event set by Delphi consensus process.

BACKGROUND: The literature does not consistently report on complications associated with arthroscopic rotator cuff repair (ARCR). Valid comparison of the occurrence of complications between ARCR interventions requires standardization. This project was implemented to define a core set of negative (untoward) events associated with ARCR along with their terms and definitions, which should be systematically documented and reported in routine care and clinical research. MATERIALS AND METHODS: A Delphi consensus process was applied. An international panel of experienced shoulder surgeons was nominated through professional societies and personal contacts. On the basis of a systematic review of terms and definitions, an organized list of relevant events associated with ARCR was developed and reviewed by panel members. Between each survey, all comments and suggestions were considered to revise the proposed core set, including local event groups along with definitions, specifications, and timing of occurrence. Consensus was defined as at least two-thirds agreement. RESULTS: Three successive online surveys were implemented involving 84 surgeons. Consensus with over 86% agreement was reached for a core list of local events including 3 intraoperative event groups (device, osteochondral, and soft tissue) and 9 postoperative event groups (device, osteochondral, pain, rotator cuff, surgical-site infection, peripheral neurologic, vascular, superficial soft tissue, and deep soft tissue). Experts agreed on a period for documentation of each event or group of events ranging from 3 to 24 months after ARCR. CONCLUSION: A structured core set of local events associated with ARCR has been developed by international consensus. Further evaluation and validation in the context of clinical studies are required.

Risk of insufficient internal rotation after bilateral reverse shoulder arthroplasty: clinical and patient-reported outcome in 57 patients.

BACKGROUND: Bilateral reverse shoulder arthroplasty (RSA) is controversial because of potential rotational deficits impairing daily living activities. We assessed achievement of insufficient internal rotation (IR) and associated factors in bilateral RSA patients. METHODS: Fifty-seven staged bilateral RSA patients with a minimum of 1 year of follow-up after the second intervention were identified from our local monocentric register. Shoulder range of motion (including IR using the Apley scratch test), strength, and Constant and Shoulder Pain and Disability Index scores were assessed preoperatively and 6, 12, and 24 months postoperatively. RESULTS: Before surgery, both shoulders were similar regarding imaging parameters, but first operated shoulders tended to have poorer function. One year after the first RSA, 21% of patients had insufficient IR (not reaching the lumbosacral junction) compared with 33% after the second intervention (P = .180). At 2 years, 5% of patients had insufficient IR on both sides. Patients with insufficient IR on the second side at baseline (relative risk [RR], 1.8 [1.0-3.2]) and patients with insufficient IR 1 year after the first RSA (RR, 3.0 [1.6-5.6]) were more likely to have insufficient IR 1 year after the second RSA. Constant and Shoulder Pain and Disability Index scores and abduction of the second side were significantly worse 1 year after the second RSA (P ≤ .047); at 2 years, there were no differences in functional outcome between shoulders. CONCLUSION: A minority of bilateral RSA patients did not achieve sufficient IR on at least 1 side. Staged surgery is justified, particularly when the outcome of the initial operation is satisfactory.

Patch-augmented rotator cuff repair: influence of the patch fixation technique on primary biomechanical stability.

INTRODUCTION: There is an ongoing debate about the potential of patch augmentation to improve biomechanical stability and healing associated with rotator cuff repair. The biomechanical properties of three different patch-augmented rotator cuff repair techniques were assessed in vitro and compared with a standard repair. Dermal collagen patch augmentation may increase the primary stability and strength of the repaired tendon in vitro, depending on the technique used for patch application. METHODS AND MATERIALS: Forty cadaveric sheep shoulders with dissected infraspinatus tendons were randomized into four groups (n = 10/group) for tendon repair using a knotless double-row suture anchor technique. A xenologous dermal extracellular matrix patch was used for augmentation in the three test groups using an "integrated", "cover", or "hybrid" technique. Tendons were preconditioned, cyclically loaded from 10 to 30 N at 1 Hz, and then loaded monotonically to failure. Biomechanical properties and the mode of failure were evaluated. RESULTS: Patch augmentation significantly increased the maximum load at failure by 61 % in the "cover" technique test group (225.8 N) and 51 % in the "hybrid" technique test group (211.4 N) compared with the non-augmented control group (140.2 N) (P ≤ 0.015). For the test group with "integrated" patch augmentation, the load at failure was 28 % lower (101.6 N) compared with the control group (P = 0.043). There was no significant difference in initial and linear stiffness among the four experimental groups. The most common mode of failure was tendon pullout. No anchor dislocation, patch disruption or knot breakage was observed. CONCLUSION: Additional patch augmentation with a collagen patch influences the biomechanical properties of a rotator cuff repair in a cadaveric sheep model. Primary repair stability can be significantly improved depending on the augmentation technique.

Patterns of proximal humeral bone resorption after total shoulder arthroplasty with an uncemented rectangular stem.

BACKGROUND: The aim of this study was to assess the timing and location of cortical bone resorption after total shoulder arthroplasty with an uncemented rectangular stem and investigate its effect on shoulder function up to 5 years after implantation. METHODS: Between June 2003 and September 2006, 183 consecutive total shoulder arthroplasties were performed, 133 of which received a cementless rectangular stem as indicated by primary or post-traumatic osteoarthritis (OA). The 5-year postoperative follow-up rate was 80%. Standardized radiographic controls and clinical assessments were performed at 6 weeks, 6 months, and 1, 2, and 5 years. RESULTS: Twenty-two patients (17%) showed full-thickness cortical bone resorption, 21 of whom were diagnosed with Sperling zone 2 resorption. The maximum craniocaudal distance of full resorption averaged 19.1 mm (range, 5.6-46.7 mm). The median distance progressed significantly from 9.6 mm to 13.8 mm between 6 and 12 months (P = .005). The risk of bone resorption was 3.1 times higher for post-traumatic OA patients than for those with primary OA. The occurrence of bone resorption increased significantly with increasing stem diameters relative to the humeral diameter. There was no significant effect of bone resorption on functional outcome. CONCLUSION: Full-thickness cortical bone resorption in the proximal posterolateral humerus after receipt of a cementless rectangular stem has a prevalence of 17%, mostly occurring within the first year after surgery. Risk factors include age, post-traumatic conditions, and larger stem sizes relative to the humerus. This is a radiographic phenomenon without significant impairment of function or need for revision within 5 years after surgery.

Clinical and radiographical results after double flip button stabilization of acute grade III and IV acromioclavicular joint separations.

INTRODUCTION: Persistent horizontal instability after acute acromioclavicular (AC) joint separation may provoke unsatisfactory results of conservative treatment. HYPOTHESIS: the arthroscopically assisted double flip button stabilization of acute horizontally unstable grade III and IV AC joint disruptions results in full functional restoration and stable radiological reposition. MATERIALS: 21 patients treated for an acute grade III or IV AC joint separation were enrolled. Clinical assessment at least 2-year postoperative included the constant score (CS) and the simple shoulder test. A panorama stress view, bilateral axial view and an AC view were obtained for radiographic evaluation. RESULTS: 19 individuals (mean 37 years; 17 men) with 16 Rockwood type III and 3 type IV injuries were available for examination 24­51 months postoperatively. The mean CS was 90.2 points (SD 6.5) with no statistically significant difference between CS and age-adjusted normative values. The mean Simple Shoulder Test scored 11.5 points (range 8­12). Loss of reduction of more than 2 mm in the coronal plane stress views was present in 6 patients (32 %) with no associated loss of functional outcome. Two of four reported complications in four patients were treated surgically (one open revision with graft augmentation for coracoid implant break out, one arthroscopic capsular release for persistent glenohumeral stiffness). CONCLUSION: Arthroscopically assisted double flip button stabilization for acute grade III and IV AC joint separation restores fully horizontal stability and age-expected shoulder function, resulting in high patient satisfaction, despite a loss of reduction observed radiographically in approximately one-third of patients. LEVEL OF EVIDENCE: IV.

Development and internal validation of a model predicting patient-reported shoulder function after arthroscopic rotator cuff repair in a Swiss setting.

BACKGROUND: Prediction models for outcomes after orthopedic surgery provide patients with evidence-based postoperative outcome expectations. Our objectives were (1) to identify prognostic factors associated with the postoperative shoulder function outcome (the Oxford Shoulder Score (OSS)) and (2) to develop and validate a prediction model for postoperative OSS. METHODS: Patients undergoing arthroscopic rotator cuff repair (ARCR) were prospectively documented at a Swiss orthopedic tertiary care center. The first primary ARCR in adult patients with a partial or complete rotator cuff tear were included between October 2013 and June 2021. Thirty-two potential prognostic factors were used for prediction model development. Two sets of factors identified using the knowledge from three experienced surgeons (Set 1) and Bayesian projection predictive variable selection (Set 2) were compared in terms of model performance using R squared and root-mean-squared error (RMSE) across 45 multiple imputed data sets using chained equations and complete case data. RESULTS: Multiple imputation using data from 1510 patients was performed. Set 2 retained the following factors: American Society of Anesthesiologists (ASA) classification, baseline level of depression and anxiety, baseline OSS, operation duration, tear severity, and biceps status and treatment. Apparent model performance was R-squared = 0.174 and RMSE = 7.514, dropping to R-squared = 0.156, and RMSE = 7.603 after correction for optimism. CONCLUSION: A prediction model for patients undergoing ARCR was developed using solely baseline and operative data in order to provide patients and surgeons with individualized expectations for postoperative shoulder function outcomes. Yet, model performance should be improved before being used in clinical routine.

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.

Reverse shoulder arthroplasty as a salvage procedure for failed conventional shoulder replacement due to cuff failure--midterm results.

Our goal was to evaluate the objective and subjective midterm outcome after revision of a failed shoulder arthroplasty with a reverse design prosthesis. Twenty consecutive patients with 21 revisions of a primary shoulder arthroplasty using reverse shoulder prosthesis Delta III(®) were followed up postoperatively for a mean of 46 months including clinical and radiological examination. Complications were recorded and Constant score, DASH and SF36 were assessed. With the numbers given a significant reduction of pain was achieved from 8.7 to 3.0 (p < 0.001). There was a significant improvement of active flexion from 43° to 97° (p < 0.001) and active abduction from 44° to 90° (p < 0.001). However, at the same time, active external rotation with an adducted humerus decreased significantly from 26° to 12° (p = 0.012). The constant score improved significantly from 16.7 to 55.9 (p < 0.001). Sixteen patients (84%) rated their shoulder better or much better than before. In 43% an intraoperative and in 38% a postoperative complication occurred including two late stage infections which required prosthesis removal. Our results support the use of the reverse prosthesis as revision prosthesis. The reverse design helps to compensate functional deficits due to severe soft-tissue damage except active external rotation. Nevertheless, the revision is a technically demanding procedure reflected in a high rate of intraoperative complications. The rate of secondary infections of 10% remains a special concern.

Biomechanical testing of rectangular humeral shaft prosthesis: higher torsional stability without increased fracture risk.

BACKGROUND: Rectangular cementless femur shaft prostheses have a higher primary stability than round shafts. A novel rectangular humeral shaft design was tested with two questions: does the rectangular design cause a higher fracture risk during implantation than round designs, and does it increase the torsional stiffness? MATERIALS AND METHODS: Two series with six paired human humeri (total 24) were tested on one side with the rectangular shaft and on the contralateral side with a round shaft. In the first series, the shaft implantation was carried out with a constant speed of 100 mm/min and the maximum force was measured when the fracture occurred. In the second series, the implants were preloaded with 50 N and then rotated at 2° per second with monitoring of the torsional torque. RESULTS: The maximum force at fracture showed no significant difference for the two designs (p = 0.34). Higher age and low bone density reduced the force required for fracture. The rectangular shaft showed significant higher torsional moments (p < 0.05). CONCLUSIONS: In biomechanical testing, the rectangular shaft had a significantly higher primary torsional stability than the round shaft without a higher risk of fracture during cementless implantation. Fracture risk and torsional stability are influenced by age and bone density.