Mid-term results of arthroscopically assisted latissimus dorsi transfer for irreparable posterosuperior rotator cuff tears.

BACKGROUND: With progress in arthroscopic surgery, latissimus dorsi transfer for irreparable posterosuperior rotator cuff tears (RCTs) has become a reliable all-arthroscopic or arthroscopically assisted procedure. The mid-term results of arthroscopically assisted latissimus dorsi transfer (aLDT) are scarce in the literature. The purpose of this study was to report our clinical and radiographic mid-term results of aLDT for irreparable posterosuperior RCTs. METHODS: Thirty-one consecutive patients with a mean age of 55.5 years (range, 38-73 years) at the time of aLDT were evaluated after a mean of 3.5 years (range, 2-5 years). All patients had irreparable, full-thickness tears of at least the complete supraspinatus, with or without infraspinatus tendons, and 12 patients (39%) had undergone previous rotator cuff repair (RCR). A concomitant upper-third subscapularis repair was needed at the time of aLDT in 7 patients (23%). Mid-term results were assessed clinically and radiographically (including magnetic resonance imaging). RESULTS: At final follow-up, 4 patients with failure (13%) had undergone revision to reverse total shoulder arthroplasty (RTSA) essentially for untreatable pain. Patients with revision to RTSA had significantly higher preoperative pain levels (Constant pain score, 6 points vs. 11 points; P = .032) and lower Constant activity scores (2 points vs. 5 points, P = .017) than the remaining 27 patients. Patients with failed previous RCRs had significantly inferior results compared with patients without previous repair (mean Subjective Shoulder Value, 67% vs. 88%; P = .035). For the 27 patients without revision, the mean relative Constant score improved from 63% to 76% (P = .032), the Constant pain score, from 10.5 to 12.7 points (P = .012), and the Subjective Shoulder Value, from 43% to 77% (P < .001). Significant progression of glenohumeral arthropathy by 2 or more grades according to the Hamada classification was observed in 13 of the 27 patients (48%), but there was no significant difference in clinical outcomes between the patients with arthropathy (n = 13) and those without it (n = 14, P = .923). CONCLUSIONS: The mid-term results of aLDT for irreparable posterosuperior RCTs were associated with significant improvements in objective and subjective outcome measures. The failure rate leading to conversion to RTSA was relatively high in this cohort. The failures were associated with unusually intense pain in low-demand individuals and/or revision of failed RCR. Long-term results of aLDT are needed to evaluate the effect of this procedure on the progression of osteoarthritis.

Stand-alone coracoclavicular suture repair achieves very good results in unstable distal clavicle fractures at a minimum follow-up of 1 year.

BACKGROUND: The treatment of unstable (Neer type IIB and V) extra-articular distal clavicle fractures remains challenging, especially when encountering a small lateral fragment which does not allow for sufficient screw purchase. It was the purpose of this study to present the clinical and radiologic outcome of a consecutive series of patients treated by a stand-alone coracoclavicular stabilization using a so-called cow-hitch technique with a suture anchor. METHODS: Nineteen patients were treated with a specific surgical technique for distal clavicle fractures (11 left, 8 right) with either rupture or bony avulsion of the coracoclavicular ligaments. Fourteen patients were examined in our outpatient clinic for the purpose of this study after a mean follow-up of 5 years (1-12.2 years). The examination included scoring according to Constant Murley score (CMS), the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), the Subjective Shoulder Value (SSV), and follow-up radiographs. Two additional patients were amenable to a telephone interview. RESULTS: All patients reported very good subjective results, with a mean SSV of 92% and a mean ASES score of 96%. The CMS resulted in average absolute values of 92 points. Fractures consolidated in 95% of cases. One patient developed an asymptomatic pseudarthrosis. The coracoclavicular distance was restored from 21 mm preoperatively to 11 mm at the final follow-up and finally showed an average side-to-side difference of +1.8 mm. Sports activities were fully resumed after an average of 4.7 months. CONCLUSION: The coracoclavicular stand-alone cow-hitch suture repair for unstable distal clavicle fractures is a minimally invasive fixation technique without prominent hardware that allows for an anatomic reduction and stable fixation with a low complication and high bony union rate. Both radiographic and clinical long-term results are very satisfactory.

Radiographic performance depends on the radial glenohumeral mismatch in total shoulder arthroplasty.

BACKGROUND: Optimal radii of curvature of the articulating surfaces of the prosthetic components are factors associated with the longevity of cemented glenoid components in anatomical total shoulder arthroplasty. It was the purpose of this study, to evaluate the radiographic and clinical performance of an anatomical glenoid component of a total shoulder arthroplasty (TSA) with respect to radial mismatch of the glenoid and humeral component. METHODS: In a retrospective study 75 TSA were analyzed for their clinical and radiographic performance with computed tomography by independent examiners using an established methodology. The study group was divided in two groups, one with mismatch < 4.5 mm (n:52) the others with mismatch ≥4.5 mm (n:23) and analyzed for confounding variables as indication, primary or revision surgery, age, gender, glenoid morphology and implant characteristics. RESULTS: The mean glenohumeral radial mismatch was 3.4 mm (range 0.5-6.9). At median follow-up of 41 months (range 19-113) radiographic loosening (defined as modified Molé scores ≥6) was present in 7 cases (9.3%). Lucencies around the glenoid pegs (defined as modified Molé score ≥ 1) were present in 34 cases (45%). Radiolucencies were significantly associated with a radial mismatch < 4.5 mm (p = 0.000). The pre- to postoperative improvements in Subjective Shoulder Value and absolute Constant Score were significantly better in the group with a mismatch ≥4.5 mm (p = 0.018, p = 0.014). CONCLUSION: A lower conformity of the radii of humerus and glenoid seems to improve the loosening performance in TSA. Perhaps cut-off values regarding the recommended mismatch need to be revalued in the future.

Little benefit of surgical anchor and suture removal and of antibiotic therapy beyond 6 weeks in infected rotator cuff repair.

BACKGROUND: The purpose of this study was to investigate the benefit of surgical anchor and/or suture removal and prolonged antibiotic therapy in acute and chronic infections of rotator cuff repair (RCIs). METHODS: A single-center cohort and case-control study (Cox regression) was performed. Outcome variables were remission of infection and postinfection reoperations due to failed tendon healing for mechanical causes. All analyses were performed with an emphasis on anchor and suture retention or removal. RESULTS: We identified 54 primary RCIs (44 men; median age 54 years) that were surgically revised (10 by open débridement and 44 by arthroscopy). Twenty-eight (52%) were not intact on revision surgery (débridement) - 10 were partially and 18 totally re-ruptured. The median number of surgical revisions was 1 (range, 1-3), and the median duration of postsurgical antibiotic therapy was 75 days. After a minimal follow-up of 2 years, 8 infections (8/54, 15%) recurred. Twenty patients needed a revision surgery; in all of those 20 patients, intraoperative samples were negative for infection. By multivariate analysis, anchor removal at the first revision influenced neither remission (hazard ratio [HR] 0.9, 95% confidence interval [CI] 0.4-2.0) nor the need for later revision surgery due to mechanical sequelae (HR 0.6, 95% CI 0.1-1.4). The corresponding HRs for suture removal were 0.9 (95% CI 0.4-1.7) and 0.4 (95% CI 0.1-1.2). Likewise, the numbers of revision surgery (HR 0.5, 95% CI 0.2-1.3) and antibiotics beyond 6 weeks failed to influence remission (HR 1.1, 95% CI 0.4-3.1). CONCLUSIONS: In our RCI cohort, the removal of anchors or sutures, repeated revision surgery, or an antibiotic therapy beyond 6 weeks failed to improve remission or to reduce sequelae.

Suprascapular nerve decompression in addition to rotator cuff repair: a prospective, randomized observational trial.

BACKGROUND: Tear and retraction of the supraspinatus (SS) and infraspinatus (IS) musculotendinous units and/or their repair may be associated with traction damage to the suprascapular nerve, potentially responsible for pain or weakness of the rotator cuff (RC). Arthroscopic release of the transverse scapular ligament at the suprascapular notch has been advocated to prevent or treat suprascapular nerve impairment associated with RC retraction and/or repair. The effect of this procedure on preoperative normal nerve function is, however, not well studied.We hypothesize that (1) decompression of the suprascapular nerve without preoperative pathologic neurophysiological findings will not improve clinical or imaging outcome and (2) suprascapular decompression will not measurably change suprascapular nerve function. METHODS: Nineteen consecutive patients with a magnetic resonance arthrography documented RC tear involving SS and IS but normal preoperative electromyography (EMG)/nerve conduction studies of the SS and IS were enrolled in a prospective, controlled trial involving RC repair with or without suprascapular nerve decompression at the suprascapular notch. Nine patients were randomized to undergo, and 10 not to undergo, a decompression of the suprascapular nerve. Patients were assessed clinically (Constant score, mobility, pain, strength, subjective shoulder value), with magnetic resonance imaging and neurophysiology preoperatively and at 3- and 12-month follow-up. RESULTS: There was no clinically relevant difference between the release and the non-release group in any clinical parameter at any time point. At magnetic resonance imaging, there was a slightly greater increase of fatty infiltration of the IS in the release group without any other differences between the 2 groups. Electromyographically, there were no pathologic findings in the non-release group at any time point. Conversely, 3 of the 9 patients of the release group showed pathologic EMG findings at 3 months, of whom 2 had recovered fully and 1 only partially at 12 months. CONCLUSION: In the presence of normal EMG findings, suprascapular nerve release added to arthroscopic RC repair is not associated with any clinical benefit, but with electromyographically documented, postoperative impairment of nerve function in 1 of 3 cases. Suprascapular nerve release does not therefore seem to be justified as an adjunct to RC repair if preoperative EMG findings document normal suprascapular nerve function. Based on these findings, the ongoing prospective randomized trial was terminated.

Neurectomy preserves fast fibers when combined with tenotomy of infraspinatus muscle via upregulation of myogenesis.

INTRODUCTION: We evaluated the contribution of denervation-related molecular processes to rotator cuff muscle degeneration after tendon release. METHODS: We assessed the levels of myogenic (myogenin and myogenic differentiation factor [myoD]) and proadipogenic (peroxisome proliferator-activated receptor γ) transcription factors; the denervation-associated proteins tenascin-C, laminin-2, and calcium/calmodulin-dependent kinase II (CaMKII); and cellular alterations in sheep after infraspinatus tenotomy (TEN), suprascapular neurectomy (NEU), or both (TEN-NEU). RESULTS: Extracellular ground substance increased at the expense of contractile tissue 16 weeks after surgery, correlating with CaMKII isoform levels. Sheep undergoing NEU and TEN-NEU had exaggerated infraspinatus atrophy and increased fast fibers compared with TEN sheep. The ßMCaMKII isoform levels increased with TEN, and myoD levels tripled after denervation and were associated with slow fibers. DISCUSSION: In sheep, denervation did not affect muscle-to-fat conversion after TEN of the infraspinatus. Furthermore, concurrent NEU mitigated the loss of fast fibers after TEN by inducing a fast-contractile phenotype. Muscle Nerve 59:100-107, 2019.

Bone autografting in medial open wedge high tibial osteotomy results in improved osseous gap healing on computed tomography, but no functional advantage: a prospective, randomised, controlled trial.

PURPOSE: Medial open wedge high tibial osteotomy (owHTO) is a valuable surgical technique used to manage medial degeneration in varus knees. Iliac crest autograft is considered the gold standard gap-filler. It was hypothesised that iliac crest autograft promotes gap healing and improves functional outcome in owHTO. METHODS: Between 2005 and 2009, patients scheduled to undergo owHTO stabilised by a medial locking compression plate were randomised to undergo owHTO either with iliac crest autograft (group A) or without bone void filler (group B). Pre- and postoperative leg axes were recorded. At 3 and 12 months postoperatively, the healing of the osteotomy gap was measured as a percentage on CT images, and functional scores were recorded. RESULTS: There were 15 patients in group A, and 25 in group B. The groups were similar in age, sex ratio, knee varus deformity, body mass index, and smoking status. Group A and B had similar preoperative varus (6.9° vs. 7.6°) and postoperative valgus (2.2° vs. 3.0°). Compared with the control group, group A had a significantly greater degree of osseous gap healing after 3 months (40.1% vs. 10.8%, p = 0.045) and 12 months (91.5% vs. 59.1%, p ≤ 0.001). Multiple linear regression analysis found that bone grafting was an independent promoting factor for gap healing, while increased preoperative varus was an independent retardant factor at 3 months (p = 0.004 and p = 0.002, respectively) and 12 months (p ≤ 0.001 and p = 0.003, respectively). Younger age was a promoting factor for gap healing on CT at 3 months (p ≤ 0.001), but not at 12 months. No correlations were found between bone healing and functional outcome, body mass index, or smoking status. CONCLUSIONS: Iliac crest autograft significantly increases healing of the osteotomy gap after owHTO. Increased preoperative varus and older patient age are independent factors that delay early healing of the osteotomy. However, no functional advantage was found at 3 or 12 months postoperatively. Therefore, routine use of iliac crest autograft cannot be recommended. LEVEL OF EVIDENCE: II.

Posterior and inferior glenosphere position in reverse total shoulder arthroplasty supports deltoid efficiency for shoulder flexion and elevation.

BACKGROUND: For humeral flexion and elevation, most relevant for daily activities with reverse total shoulder arthroplasty, the anterior and lateral deltoid muscles are most important. However, how this direction of movement is best supported with the glenosphere position is not fully understood. We hypothesized that both inferior positioning and posterior positioning of the glenosphere may best support this direction of movement. METHODS: A validated, anatomic biomechanical shoulder model was modified to host a reverse shoulder prosthesis. The glenoid baseplate was altered to allow inferior, lateral, and posterior center-of-rotation (COR) offsets. An optical tracking system was used to track the excursion of ropes simulating portions of various shoulder muscles during humeral abduction, elevation, and flexion. RESULTS: The inferior COR offset resulted in a significant increase in the deltoid moment arm in all 3 planes of motion. The lateral COR offset showed a significantly lower posterior deltoid moment arm during humeral abduction and a significantly lower lateral deltoid moment arm during humeral elevation. The posterior offset showed significantly larger anterior and lateral deltoid moment arms during humeral flexion. DISCUSSION AND CONCLUSION: Owing to the oblique direction of the deltoid muscle across the shoulder joint, an inferior offset of the COR in reverse total shoulder arthroplasty increases the deltoid moment arm during abduction, elevation, and flexion, whereas it mainly supports humeral flexion at a posterior offset. For humeral elevation and flexion, favorable positioning of the glenosphere may, therefore, be defined by a more inferior and posterior placement compared with the non-offset position.

Small anteroposterior inclination of the acromion is a predictor for posterior glenohumeral erosion (B2 or C).

BACKGROUND: Anatomic factors associated with static posterior translation of the humeral head with or without glenohumeral osteoarthritis are unknown. We tested the hypothesis that there is an association between glenoid wear, glenoid version, and/or anteroposterior acromial tilt. METHODS: Ninety-nine patients with glenohumeral joint degeneration involving advanced glenoid cartilage wear and/or rotator cuff disease scheduled for anatomic or reverse total shoulder replacement underwent standardized conventional radiographic and computed tomographic shoulder imaging. Measurements included glenoid version, humeral torsion, posterior acromial slope, and critical shoulder angle. The glenoid shape was classified according to Walch et al, and the integrity of the rotator cuff was assessed. RESULTS: Patients with glenoid type B2 or C had a median of 4° more glenoid retroversion (P = .022), a 5° less steep acromion (posterior acromial slope, 61° vs 56°; P = .004), and a higher combined score (glenoid version minus slope; odds ratio, 0.93 [95% confidence interval, 0.89-0.97]; P < .001; cutoff, -27°) than those with type A or B1. When the rotator cuff was torn, osteoarthritic changes were milder than when the cuff was intact (eg, P < .001 for supraspinatus). CONCLUSION: The study's hypothesis that the bony anatomy of the scapula and in particular the acromion is correlated with the type of glenoid wear was confirmed. Both a more horizontal acromial orientation in the sagittal plane and increased posterior glenoid version are found in osteoarthritis of the shoulder associated with eccentric, posterior glenoid wear. Tears of the rotator cuff are significantly associated with concentric osteoarthritis of the glenoid.

Staged Revision With Antibiotic Spacers for Shoulder Prosthetic Joint Infections Yields High Infection Control.

BACKGROUND: The treatment of periprosthetic joint infection (PJI) of the shoulder with two-stage revision arthroplasty using an antibiotic-loaded cement spacer is established strategy, but there is sparse information regarding the likelihood of infection control and restoration of shoulder. QUESTIONS/PURPOSE: (1) What is the likelihood of infection control after two-stage revision using an antibiotic cement spacer for patients with PJI of the shoulder? (2) What are the improvements in Constant and Murley scores at 2 years after these staged revisions? PATIENTS AND METHODS: Between 2000 and 2013, we treated 48 patients with PJI of the shoulder using two-stage revision including an antibiotic-containing cement spacer during the first stage. Of those, 38 (79%) were available for review at a minimum of 24 months (mean, 52 ± 34 months). Ten patients (21%) were excluded because they were deceased (n = 3), moved abroad (n = 4), or refused followup (n = 3), leaving 38 for analysis in this retrospective study. During the first stage, removal of the prosthesis, débridement, and implantation of a gentamicin and vancomycin-filled cement spacer were performed by four different surgeons followed by antibiotic therapy (2 weeks intravenous plus 10 weeks oral). For the second stage, we generally tried a reverse total shoulder arthroplasty (RTSA; n = 26). In case of severe glenoid destruction, hemiarthroplasty (HA; n = 8) was used as a salvage option. In 14 patients the cement spacer was left in place because the patients refused further surgery or were not operable owing to medical reasons. The primary outcome included the proportion of patients achieving infection control 2 years after the second-stage procedure after implantation of the cement spacer. Infection control was determined as the absence of the Musculoskeletal Infection Society PJI criteria. The clinical outcome assessed with the Constant and Murley scores served as the secondary outcome parameter. A subgroup (RTSA; HA, spacer retention) analysis of the Constant and Murley scores was performed. RESULTS: Successful infection control was achieved in 36 of 38 patients (95%). Patients who underwent treatment with a cement spacer had increased Constant and Murley scores at latest followup compared with their pretreatment scores (mean ± SD, 27 ± 19 versus 43 ± 20; mean difference, 17; 95% CI, 10-24; p = 0.001). For patients who underwent staged treatment followed by second-stage RTSA (n = 23), the Constant and Murley scores increased (mean ± SD, 31 ± 20 versus 51 ± 20; mean difference, 20; 95% CI, 11-30; p = 0.001). The Constant and Murley scores did not improve in patients who underwent HA (mean ± SD, 22 ±15 versus 24 ± 90; mean difference, 3; 95% CI, -10 to 16; p = 0.509) or who retained the spacer (mean ± SD, 18 ±12 versus 35 ±10; mean difference, 19; 95% CI, -5 to 44; p = 0.093). CONCLUSION: Revision arthroplasty using an antibiotic-loaded cement spacer provided successful infection control in patients with periprosthetic shoulder infections in this small, retrospective series. Functional improvement was obtained after reimplantation of a reverse total shoulder prosthesis but was not seen after HA and cement spacer; however, baseline differences among patient groups very likely contributed to these differences, and they should not be attributed to implant selection alone. LEVEL OF EVIDENCE: Level III, therapeutic study.

Influence of the site of acromioplasty on reduction of the critical shoulder angle (CSA) - an anatomical study.

BACKGROUND: A large critical shoulder angle (CSA) >35° is associated with the development of rotator cuff tearing. Lateral acromioplasty (AP) has the theoretical potential to prevent rotator cuff tearing and/ or to reduce the risk of re-tears after repair. It is, however unclear which part of the lateral acromion has to be reduced to obtain the desired CSA. It was the purpose of this study to determine which part of the lateral acromion has to be resected to achieve a desired reduction of the CSA in a given individual. METHODS: First, the influence of the exact radiographic projection on the CSA was examined. Second, the influence of anterolateral versus strict lateral AP on the CSA was studied in eight scapulae with different anatomic characteristics. Differences in CSA reduction were investigated using paired t-test or Wilcoxon test. RESULTS: Scapular rotation in the sagittal and axial plane had a marked influence on the radiologically measured CSA ranging from -6 to +16°. Overall, lateral AP of 5/10mm reduced the CSA significantly greater than anterolateral AP of 5mm/10mm [5mm: 2.3° (range: 0.7°-3.6°) SD±0.8° vs. 1.2° (range: 0°-3.3°) SD±1.1°, p=0.0002]/[10mm: 4.8° (range: 2.1°-7°) SD±1.3° vs. 2.7° (range: 0°-5.3°) SD±1.7°, p=0.0001]. Depending on scapular anatomy anterolateral AP did not alter CSA at all. CONCLUSIONS: For comparison of pre- and postoperative CSA, the exact orientation of the X-ray and the spatial orientation of the scapula must be as identical as possible. Anterolateral AP may not sufficiently correct CSA in scapulae with great acromial slopes and smaller relative external rotation of the acromion as the critical acromial point (CAP) may be located too posteriorly and thus is not addressed by anterolateral acromioplasty. Consistent reduction of the CSA could be achieved by lateral AP in all eight scapulae.

Efficacy of standardized training on a virtual reality simulator to advance knee and shoulder arthroscopic motor skills.

BACKGROUND: Most studies demonstrated, that training on a virtual reality based arthroscopy simulator leads to an improvement of technical skills in orthopaedic surgery. However, how long and what kind of training is optimal for young residents is unknown. In this study we tested the efficacy of a standardized, competency based training protocol on a validated virtual reality based knee- and shoulder arthroscopy simulator. METHODS: Twenty residents and five experts in arthroscopy were included. All participants performed a test including knee -and shoulder arthroscopy tasks on a virtual reality knee- and shoulder arthroscopy simulator. The residents had to complete a competency based training program. Thereafter, the previously completed test was retaken. We evaluated the metric data of the simulator using a z-score and the Arthroscopic Surgery Skill Evaluation Tool (ASSET) to assess training effects in residents and performance levels in experts. RESULTS: The residents significantly improved from pre- to post training in the overall z-score: - 9.82 (range, - 20.35 to - 1.64) to - 2.61 (range, - 6.25 to 1.5); p < 0.001. The overall ASSET score improved from 55 (27 to 84) percent to 75 (48 to 92) percent; p < 0.001. The experts, however, achieved a significantly higher z-score in the shoulder tasks (p < 0.001 and a statistically insignificantly higher z-score in the knee tasks with a p = 0.921. The experts mean overall ASSET score (knee and shoulder) was significantly higher in the therapeutic tasks (p < 0.001) compared to the residents post training result. CONCLUSIONS: The use of a competency based simulator training with this specific device for 3-5 h is an effective tool to advance basic arthroscopic skills of resident in training from 0 to 5 years based on simulator measures and simulator based ASSET testing. Therefore, we conclude that this sort of training method appears useful to learn the handling of the camera, basic anatomy and the triangulation with instruments.

Different acromial roof morphology in concentric and eccentric osteoarthritis of the shoulder: a multiplane reconstruction analysis of 105 shoulder computed tomography scans.

BACKGROUND: The pathomechanisms of eccentric osteoarthritis of the shoulder remain unclear. Although there is increasing evidence of bony differences between shoulders with rotator cuff tears and osteoarthritis, analogous differences have not been identified for primary concentric and eccentric osteoarthritis. This study examined the shape and orientation of the acromial roof as a potential risk factor for the development of posterior glenoid wear. METHODS: We analyzed computed tomography images of 105 shoulders with primary osteoarthritis. Based on the classification of Walch, 45 shoulders had concentric osteoarthritis (Walch A) and 60 shoulders were affected by eccentric osteoarthritis (Walch B; EOA). A comparison of acromial morphology was performed in a multiplanar reconstruction analysis of computed tomography scans. RESULTS: Acromial shape: Acromial length, width, and area were not significantly different. Acromial roof orientation: The acromial roof in EOA was an average of 5° flatter (sagittal tilt; P < .01) and 5° more downward tilted (coronal tilt; P < .01). There was no difference in axial rotation (axial tilt; P = .47). Anteroposterior glenoid coverage: The glenoid in EOA was covered an average of 4° less posteriorly (P = .01) and 4° more anteriorly (P = .04). No differences were shown for overall glenoid coverage. CONCLUSIONS: The acromial roof could play a role in the pathogenesis of EOA. Less posterior support due to a flatter acromion with less posterior glenoid coverage could contribute to static posterior subluxation of the humeral head and posterior glenoid wear. Further biomechanical investigations are needed to confirm these findings.

Acromial roof in patients with concentric osteoarthritis and massive rotator cuff tears: multiplanar analysis of 115 computed tomography scans.

BACKGROUND: There is evidence for differences of scapular shape between shoulders with rotator cuff tears (RCT) and osteoarthritic shoulders (OA). This study analyzed orientation and shape of the acromion in patients with massive RCT and concentric OA (COA) in a multiplanar computed tomography (CT) analysis. METHODS: CT scans of 70 shoulders with degenerative RCT and 45 shoulders with COA undergoing primary shoulder arthroplasty were analyzed. The 2 groups were compared in relation of (1) shape of the acromion, (2) its orientation in space, and (3) the anteroposterior glenoid coverage in relation to the scapular plane. RESULTS: Lateral acromial roof extension was an average of 4.6 mm wider and the acromial area was an average of 156 mm2 larger in RCT than in COA (P < .001). Significant differences of the lateral extension of the acromion margin were limited to the anterior two-thirds. Acromial roof orientation in RCT was average of 10.8° more "externally rotated" (axial plane: P < .001) and an average of 7.8° more tilted downward (coronal plane: P < .001) than in COA. The glenoid in RCT was an average of 5.5° (P < .001) more covered posteriorly compared with COA. CONCLUSIONS: A more externally rotated (axial plane), more downward tilted (coronal plane), and wider posterior covering acromion was more frequent in patients with massive RCT than COA.

Long-term results of total elbow arthroplasty in patients with hemophilia.

HYPOTHESIS: It was hypothesized that the long-term survivorship and clinical outcome are reasonable, justifying total elbow arthroplasty (TEA) in patients with end-stage hemophilic arthropathy. METHODS: From 2002 to 2012, 13 primary TEAs (Coonrad-Morrey design) were implanted in 9 consecutive patients with an average age of 55 (range, 39-76) years. Type A hemophilia was diagnosed in 7 patients and type B hemophilia in 2 patients. Clinical and radiographic results of all (11 TEAs) but 1 patient were retrospectively analyzed. RESULTS: After a mean of 9.1 (range, 5-14) years, the mean visual analog scale score for pain, total Mayo Elbow Performance Score, and subjective elbow value were significantly improved from 5 (standard deviation, ±3) to 2 (±2; P = .007) points, from 64 (±16) to 89 (±11; P = .008) points, and from 47% (±15%) to 81% (±11%; P < .001), respectively. Whereas the flexion arc remained unchanged (P = .279), mean active pronation improved significantly (P = .024). Postoperative complications were recorded in 8 TEAs (62%), whereas 5 TEAs (38%) underwent partial component exchange after a mean of 7.2 (range, 3-10) years: 2 for periprosthetic infection, 2 for polyethylene wear, and 1 for humeral component loosening. Of the living patients after partial component exchange (n = 3), the mean final total Mayo Elbow Performance Score, flexion and rotation arc, visual analog scale score for pain, and subjective elbow value were comparable with the results of the living patients without revision surgery (n = 8). CONCLUSIONS: TEA for patients with advanced hemophilic arthropathy is associated with a substantial complication and revision rate. However, even after revision without implant removal, it provides good functional and subjective long-term results.

Computer-assisted planning and patient-specific guides for the treatment of midshaft clavicle malunions.

BACKGROUND: The surgical treatment of malunions after midshaft clavicle fractures is associated with a number of potential complications and the surgical procedure is challenging. However, with appropriate and meticulous preoperative surgical planning, the surgical correction yields satisfactory results. The purpose of this study was to provide a guideline and detailed overview for the computer-assisted planning and 3-dimensional (3D) correction of malunions of the clavicle. METHODS: The 3D bone surface models of the pathologic and contralateral sides were created on the basis of computed tomography data. The computer-assisted assessment of the deformity, the preoperative plan, and the design of patient-specific guides enabling compression plating are described. RESULTS: We demonstrate the benefit and versatility of computer-assisted planning for corrective osteotomies of malunions of the midshaft clavicle. In combination with patient-specific guides and compression plating technique, the correction can be performed in a more standardized fashion. We describe the determination of the contact-optimized osteotomy plane. An osteotomy along this plane facilitates the correction and enlarges the contact between the fragments at once. We further developed a technique of a stepped osteotomy that is based on the calculation of the contact-optimized osteotomy plane. The stepped osteotomy enables the length to be restored without the need of structural bone graft. The application of the stepped osteotomy is presented for malunions of the clavicle with shortening and excessive callus formation. CONCLUSIONS: The 3D preoperative planning and patient-specific guides for corrective osteotomies of the clavicle may help reduce the number of potential complications and yield results that are more predictable.

Reverse total shoulder arthroplasty for failed open reduction and internal fixation of fractures of the proximal humerus.

BACKGROUND: Open reduction and internal fixation (ORIF) of complex fractures of the proximal humerus may yield unsatisfactory results. This study analyzed the results obtained after revision of failed ORIF of proximal humeral fractures using reverse total shoulder arthroplasty (RTSA). METHODS: Fifty-four shoulders of 53 patients with a subjectively unacceptable outcome after ORIF of a complex fracture of the proximal humerus were revised with RTSA. At a minimum follow-up of 2 years (mean follow-up, 46 months; range, 24-108 months), 44 shoulders were clinically and radiographically reviewed for the purpose of this study. Six patients had been lost to follow-up, and 4 patients (7%) were excluded from functional analysis because of revision surgeries. RESULTS: The mean absolute Constant score improved from 26 (range, 4-54) to 55 (range, 19-80) points; the mean relative Constant score improved from 32% (range, 4%-85%) to 67% (range, 27%-94%) of an age- and gender-matched, normal shoulder. The mean subjective shoulder value improved from 29% (range, 0%-90%) preoperatively to 67% (range, 5%-95%) at final follow-up. Nineteen patients rated their outcome excellent, 16 good, and 7 fair; 2 patients were dissatisfied. CONCLUSION: RTSA is a valuable salvage procedure after failed ORIF of a proximal humeral fracture with relatively low revision rates. Shoulder function, patient satisfaction, and pain levels can be reliably improved.

Risk factors for glenoid erosion in patients with shoulder hemiarthroplasty: an analysis of 118 cases.

BACKGROUND: Glenoid erosion is one of the main concerns in shoulder hemiarthroplasty. The goal of this study was to quantify glenoid erosion and to identify risk factors in patients with humeral hemiarthroplasty. METHODS: There were 118 shoulders in 113 patients available for a standardized retrospective review. Erosion was graded as follows: grade 1, none; grade 2, mild (erosion into subchondral bone); grade 3, moderate (medialization of subchondral bone with hemispheric deformation); or grade 4, severe. The findings were then analyzed for confounding factors using a multivariate analysis. RESULTS: Mean follow-up was 31 months (range, 5-86 months). Negative predisposing factors for erosion were glenoid cysts (odds ratio, 5.4; P < .001, approximately 3 times more frequent in women), fatty infiltration of the rotator cuff musculature (R, 0.43; P < .001), and rheumatoid arthritis (odds ratio, 3.6; P = .049). A valgus position of the prosthetic head relative to the glenoid (angle >50°) appeared to lead to local destruction of the cartilage. The degree of erosion did not correlate with age and glenoid or humeral head size. Only 1 patient (of 30) with a fracture-type prosthesis developed progressive glenoid erosion. CONCLUSION: In this series, favorable conditions for resistance to erosion after hemiarthroplasty were lack of glenoid cysts, intact glenoid cartilage, intact rotator cuff musculature, and a fracture situation. Age, the version of the glenoid, and the size of the prosthetic head showed no importance. The use of hemiarthroplasty seems to be associated with glenoid destruction in female patients with impending osteoarthritis, with rheumatoid arthritis, and if the head is implanted in a valgus position.

Dithiocarbamate Self-Assembled Monolayers as Efficient Surface Modifiers for Low Work Function Noble Metals.

Tuning the work function of the electrode is one of the crucial steps to improve charge extraction in organic electronic devices. Here, we show that N,N-dialkyl dithiocarbamates (DTC) can be effectively employed to produce low work function noble metal electrodes. Work functions between 3.1 and 3.5 eV are observed for all metals investigated (Cu, Ag, and Au). Ultraviolet photoemission spectroscopy (UPS) reveals a maximum decrease in work function by 2.1 eV as compared to the bare metal surface. Electronic structure calculations elucidate how the complex interplay between intrinsic dipoles and dipoles induced by bond formation generates such large work function shifts. Subsequently, we quantify the improvement in contact resistance of organic thin film transistor devices with DTC coated source and drain electrodes. These findings demonstrate that DTC molecules can be employed as universal surface modifiers to produce stable electrodes for electron injection in high performance hybrid organic optoelectronics.

Tendon Collagen Crosslinking Offers Potential to Improve Suture Pullout in Rotator Cuff Repair: An Ex Vivo Sheep Study.

BACKGROUND: The suture-tendon interface is often the weakest link in tendon to bone repair of massive rotator cuff tears. Genipin is a low-toxicity collagen crosslinker derived from the gardenia fruit that has been shown to augment collagen tissue strength and mechanically arrest tendon-tear progression. QUESTION/PURPOSE: The purpose of the current study was to evaluate whether genipin crosslinking can sufficiently augment the suture-tendon interface to improve suture pullout strength using simple single-loop sutures and the modified Mason-Allen technique. The study also aimed to assess whether time of genipin treatment is a relevant factor in efficacy. METHODS: In an ex vivo (cadaveric) sheep rotator cuff tendon model, a total of 142 suture pullout tests were performed on 32 infraspinatus tendons. Each tendon was prepared with three single-loop stitches. Two groups were pretreated by incubation in genipin solution for either 4 hours or 24 hours. Two corresponding control groups were incubated in phosphate buffered saline for the same periods. The same test protocol was applied to tendons using modified Mason-Allen technique stitch patterns. Each suture was loaded to failure on a universal materials testing machine. Suture pullout force, stiffness, and work to failure were calculated from force-displacement data, and then compared among the groups. RESULTS: Median single-loop pullout force on tendons incubated for 24 hours in genipin yielded an approximately 30% increase in maximum pullout force for single-loop stitches with a median of 73 N (range, 56-114 N) compared with 56 N (range, 40-69 N; difference of medians = 17 N; p = 0.028), with corresponding increases in the required work to failure but not stiffness. Genipin treatment for 4 hours showed no added benefit for suture-pullout behavior (46 N, [range, 35-95 N] versus 45 N, [range, 28-63 N]; difference of medians, 1 N; p = 1). No tested genipin crosslinking conditions indicated benefit for tendons grasped using the modified Mason-Allen technique after 4 hours (162 N, [range, 143-193 N] versus 140 N, [range, 129-151 N]; difference of medians, 22 N; p = 0.114) or after 24 hours of crosslinking (172 N, [range, 42-183 N] versus 164 N [range, 151-180 N]; difference of medians, 8 N; p = 0.886). CONCLUSION: Exogenous collagen crosslinking in genipin can markedly improve resistance to pullout at the tendon-suture interface for simple stitch patterns while the modified Mason-Allen stitch showed no benefit in an ex vivo animal model. CLINICAL RELEVANCE: Tendon strength augmentation by genipin pretreatment offers the potential to improve suture retention properties. Future studies are warranted for the development of clinically viable intraoperative delivery strategies and in vivo testing for safety and efficacy.