How shoulder immobilization after surgery influences daily activity - a prospective pedometer-based study.

PURPOSE: Immobilization, especially of the lower extremity, after orthopaedic surgery has been associated with reduced physical activity. Previous interventions from our study group showed even in young, healthy people reduced activity levels after immobilization of the shoulder. Therefore, this study investigates the change in physical activity due to shoulder immobilization after a reconstructive surgery. METHODS: This prospective study includes 40 patients undergoing surgery from May 2019 to December 2020. Daily activity was measured before surgery, after discharge and three weeks postoperatively each time for six days. Activity including step counts and active time were measured by Fitbit™ inspire. Range of motion before and after surgery as well as Pain (VAS) were documented. RESULTS: Steps became significantly less immediately postoperatively with an immobilized shoulder joint than before surgery (9728.8 vs. 6022.6, p < 0.05). At follow-up, the number of steps increased again, but still showed a significantly lower number of steps (mean 8833.2) compared to preoperative. Patients preoperatively showed mostly an "active" activity pattern, whereas postoperatively a "low active" behaviour predominated. The proportion of sedentary behaviour ("basal activity" and "limited activity") was almost three times higher postoperatively (12.5% vs. 30%). CONCLUSION: General physical activity is restricted during upper limb immobilization in adults. Therefore, activity-enhancing measures should be implemented in the early phase of rehabilitation after upper extremity surgery.

Single-row vs. double-row refixation of the subscapularis tendon after primary anatomic shoulder arthroplasty.

BACKGROUND: The postoperative integrity of the subscapularis tendon after primary anatomical shoulder arthroplasty has a significant effect on postoperative results. A transosseus Single Row Refixation technique (SRR) has shown up to 30% of partial tears in literature, a modified Double Row Refixation technique (DRR) has biomechanically shown a significantly reduced tear rate, but is yet to be proven in a clinical setting. Thus, we compared the SRR to the DRR technique using clinical outcome parameters and ultrasound examination. MATERIALS AND METHODS: 36 patients (40 shoulders; 20f, 16 m; øage: 66 years) were included in our retrospective cohort study. 20 shoulders were treated with the SRR technique (12f, 8 m; FU ø40.9 months) and 20 with the DRR technique (11f, 9 m; FU ø31.6 months). The SRR was performed with three to five transosseus mattress sutures. DRR consisted of two medial placed transosseus sutures and four laterally placed single tendon-to-tendon sutures. The postoperative subscapularis integrity was evaluated by ultrasound examination, the clinical outcome was assessed with the Constant-Murley Score (CS) and the American Shoulder and Elbow Surgeons Score (ASES). RESULTS: The subscapularis tendon was intact in 14 patients (70%) after SRR, whereas 18 patients (90%) treated with the DRR demonstrated a sonographically intact postoperative subscapularis tendon. The CS was 61.4 points in the SRR cohort and 67.3 points in the DRR cohort (p = 0.314). No significant differences were found in both cohorts preoperative (øSRR: 21.3 points; øDRR: 16.2 points, p = 0.720) and postoperative absolute ASES Scores (øSRR: 70.2 points; øDRR: 73.0 points, p = 0.792). However, the DRR cohort showed a statistical tendency to a higher postoperative ASES increase than the SRR cohort (øSRR-ASES increase: 48.9 points; øDRR-ASES increase: 56.8 points, p = 0.067). CONCLUSION: The results of this study show that application of the DRR technique can significantly reduce the total rate of postoperative subscapularis tears what effects a clinical tendency towards higher ASES improvements and a better range of motion compared to the SRR technique.

How shoulder immobilization influences daily physical activity - an accelerometer based preliminary study.

BACKGROUND: To investigate the influence of shoulder immobilization on daily physical activity. INTRODUCTION: The harmful effect of sedentary behavior does not receive much attention in orthopedic surgery even though immobilization, especially of the lower extremity, has been associated with reduced physical activity. Immobilization of the shoulder is common after reconstructive shoulder surgery and could also potentially lead to reduced physical activity and have a negative effect on a patient's general health. METHOD: Twenty-one healthy volunteers were immobilized in an orthosis (DJO Ultrasling III) for 10 h on two consecutive days. In the following week, activity was measured on the same days without the orthosis. Activity including gait cycles per minute and total gait cycles per day was measured by accelerometer based step count StepWatchTMActivity Monitor. Average age was 26 +/- 3 years. A questionnaire was administered to evaluate subjective activity. RESULTS: Participants wearing the shoulder orthosis were significantly less active than without immobilization by 2227.5 gait cycles/day (5501.2 with SO, 7728.7 without SO). Also, significantly more time in sedentary behavior occurred (< 400 steps/h) when the shoulder was immobilized. Patients were significantly more active without shoulder orthosis in medium level activities (800-999 steps/h). Differences for low (400-799 steps/h) and high activity levels (> 1000 steps/h) were not statistically significant. Subjective limitations while wearing the orthosis were graded at 2.343 on a scale of 0-4. CONCLUSION: Results of this study show that even in young, healthy volunteers immobilization of the shoulder in an orthosis for 2 days leads to significantly reduced activity levels. A negative influence on general health, especially in older patients who are immobilized for up to 6 weeks, can potentially occur. Promoting physical activity during the immobilization period should be part of rehabilitation after injuries/surgery of the shoulder. TRIAL REGISTRATION: Retrospectively registered in DRKS (DRKS00017636).

Subtle changes of gray matter volume in fibromyalgia reflect chronic musculoskeletal pain rather than disease-specific effects.

Fibromyalgia syndrome (FMS) is a chronic pain syndrome. Neuroimaging studies provided evidence of altered gray matter volume (GMV) in FMS but, similarly, in chronic pain of other origin as well. Therefore, the purpose of this study was to evaluate the disease specificity of GMV alterations in FMS by direct comparison. Structural MRI data of the brain were acquired in 25 females with FMS and two different control groups: 21 healthy subjects and 23 patients with osteoarthritis. Regional GMVs were compared by voxel-based morphometry and additional ROI-analyses. In conclusion, we did not identify significant GMV alterations in either FMS or OA patients compared to healthy controls when adopting a conservative statistical approach with multiple comparison correction. However, even under a more liberal approach no FMS-specific GMV changes were found because both pain groups presented increased gray matter volumes in the precentral gyrus and decreased GMV in the angular gyrus/middle occipital gyrus and middle temporal gyrus in comparison with healthy controls. Since no differences between both pain groups could be detected cortical GMV changes in FMS should not be interpreted as FMS-specific but might rather reflect changes in chronic pain in general. This previously held notion is confirmed in this study by direct comparison with a control group consisting of another pain disorder.

Megaprosthetic replacement of the distal humerus: still a challenge in limb salvage.

BACKGROUND: The distal humerus is a rare location of bone tumors. Because of the complexity of the elbow joint, poor soft-tissue coverage, and proximity of nerves and vessels, resection and endoprosthetic reconstruction are demanding. METHODS: This retrospective study evaluated the clinical results after distal humeral resection and megaprosthetic reconstruction in 12 patients with an average age of 46 years. All patient files were reviewed for clinical information, and postoperative function and patients' contentment were assessed using the Musculoskeletal Tumor Society score. RESULTS: The predominant diagnoses were bone and soft-tissue sarcoma (n = 6), giant cell tumor (n = 2), and renal cell carcinoma metastasis (n = 2). Local recurrence was the reason for secondary amputation in all cases (n = 3). The prosthetic survival rate after surgery was 82% at 2 years and 64% at 5 years. Reconstruction failure was mainly caused by aseptic loosening of the humeral stem, occurring in 27% (n = 3), followed by aseptic loosening of the ulnar stem in 9% (n = 1) and periprosthetic infection in 9% (n = 1). The mean Musculoskeletal Tumor Society score was 24 points (range, 20-30 points). An extension lag of more than 10° was noted in 6 patients (55%). CONCLUSION: Our results suggest that limb salvage with a distal humeral replacement can achieve good functional results in most patients, although the complication rate with special emphasis on the loosening rate of the humeral stem is high. However, limb salvage was not achieved in 27% of patients because of local recurrence.

Adaptive Changes on the Dominant Shoulder of Collegiate Handball Players-A Comparative Study.

Vogler, T, Schorn, D, Gosheger, G, Kurpiers, N, Schneider, K, Rickert, C, Andreou, D, and Liem, D. Adaptive changes on the dominant shoulder of collegiate handball players-A comparative study. J Strength Cond Res 33(3): 701-707, 2019-Handball players are susceptible to adaptive bony and soft-tissue changes of the dominant shoulder. Our goal was to compare the glenohumeral range of motion and posterior capsule thickness between the dominant and nondominant arm of throwing athletes and between the dominant arm of nonthrowers and throwing athletes. Twenty-three collegiate handball players and 23 nonthrowing athletes underwent an examination of the dominant and the nondominant shoulder. Humeral retroversion and posterior capsule thickness were assessed with an ultrasound examination, whereas external rotation and internal rotation were determined with a digital inclinometer. The dominant shoulder of handball players had a significantly higher external rotation compared with their nondominant shoulder and the dominant shoulder of nonthrowing athletes. Furthermore, the dominant shoulder of handball players had a significantly lower internal rotation compared with their nondominant shoulder, with no differences compared with the dominant shoulder of the nonthrowing athletes. There was a trend for an increased posterior capsule thickness and an increased humeral retroversion between the dominant and the contralateral shoulder of handball players. Moreover, we found a significant increase in the capsule thickness of the dominant shoulder of throwing athletes compared with the dominant shoulder of nonthrowers. However, there were no differences in humeral retroversion. Our analysis suggests that a comparison of the dominant shoulder of overhead throwing athletes with the dominant shoulder of nonthrowing athletes might be more appropriate than the comparison of the dominant and the nondominant shoulder to evaluate the adaptive changes on the dominant side.

Long-term outcomes after combined arthroscopic medial reefing and lateral release in patients with recurrent patellar instability - a retrospective analysis.

BACKGROUND: There is currently no consensus regarding the optimal surgical treatment method for patients with recurrent patella instability. Our goal was to evaluate the long-term results of combined arthroscopic medial reefing and lateral release, to identify possible risk factors for recurrent dislocations and residual complaints after surgical treatment and to assess functional outcome. METHODS: We performed a retrospective study of 38 patients (43 knees) treated with all-inside technique between 2001 and 2010. The functional outcome was evaluated with the Kujala score, while pain intensity was scored on a visual analogue scale (VAS). Contingency tables were analysed with Fisher's exact test. Non-parametric analyses were carried out with the Mann-Whitney U and the Wilcoxon signed-rank test. Survival curves were calculated with the Kaplan-Meier method and compared with the log-rank test. RESULTS: The median age at surgery was 16 years (range, 9-44 years) and the median follow-up amounted to 9.7 years (range, 4.7-14.7 years). Residual complaints were present in 34 cases (79%). Patients with residual complaints had a trend for a higher body mass index (BMI) at surgery (25.7 vs. 21.6, P = .086). Twenty-two cases had recurrent dislocation after a median interval of 30 months. The probability of recurrent dislocations amounted to 16% after 1 year and 52% after 10 years. There were no significant differences in the presence of residual complaints (P = .721) and median VAS score (P = .313) between patients with or without recurrent dislocation. Patients with recurrent dislocations had a trend towards younger age at surgery (15 vs. 18 years, P = .076). The median Kujala score of the affected knee was 81. Patients with recurrent dislocations had a significantly lower score compared to patients without recurrent dislocations (67 vs. 91, P < .001). CONCLUSIONS: The combined arthroscopic lateral release with medial reefing does not appear to be an adequate treatment for patients with chronic patellar instability in long-term follow-up. Younger patients might be at a higher risk for recurrent dislocations, while a higher BMI at surgery might be associated with residual complaints.

Conversions from anatomic shoulder replacements to reverse total shoulder arthroplasty: do the indications for initial surgery influence the clinical outcome after revision surgery?

INTRODUCTION: The most frequent indications for anatomic shoulder replacement are glenohumeral osteoarthritis and fractures of the humeral head. If anatomic shoulder prostheses fail, reverse total shoulder arthroplasty is often the only remaining treatment option. This study evaluates the influence of indications for primary shoulder arthroplasty on the clinical outcome after conversion to reverse total shoulder arthroplasty. MATERIALS AND METHODS: From 2010 to 2012, 44 failed shoulder arthroplasties were converted to reverse total shoulder arthroplasty. Forty-four patients were available for follow-up after a mean of 24 months (14-36 months). Twenty-three of them had received an initial shoulder replacement because of osteoarthritis, while the remaining 21 patients had been treated for a fracture of the humeral head. At follow-up, patients were assessed with X-rays, constant-, and ASES scores. RESULTS: The total number of observed complications was higher in patients revised because of failed fracture arthroplasty (24 vs. 9%). Patients initially treated for osteoarthritis achieved a higher ASES score (71 vs. 59 points; p = 0.048). The normalized constant score was not different between the two observed groups (osteoarthritis 73% vs. fracture 67%: p = 0.45). Complications occurred more often in patients who had initially suffered from a fracture of the humeral head (fracture 23.8% vs. osteoarthritis 8.7%). Scapular notching was more frequent after initial fracture arthroplasty (33 vs. 14%). CONCLUSION: Indications for initial shoulder replacement have an influence on the clinical outcome after conversion to reverse total shoulder arthroplasty. Patients initially treated for a fracture of the humeral head have a lower subjective outcome and a higher complication rate in comparison with patients initially treated for osteoarthritis. LEVEL OF EVIDENCE: IV (Retrospective study).

Cold versus cold compression therapy after shoulder arthroscopy: a prospective randomized clinical trial.

PURPOSE: Purpose of the present study was to investigate the acute effects of a cold compression bandage on pain, swelling and skin-surface temperature after the first 24 h after arthroscopic surgery of the shoulder in a stationary setting and to compare it with cold therapy using only a cold pack. It was hypothesized that using the bandage is more effective in reducing pain and swelling after 24 h compared with using only a cold pack. METHODS: Fifty-two patients (53 ± 12.2 years) were randomly assigned to two groups after arthroscopic surgery. The first group wore a cold compression bandage, and the second group a conventional frozen cold pack. Pain, swelling and skin-surface temperature were measured 2, 8 and 24 h after surgery. Differences within and between groups were analysed. RESULTS: Both groups showed a significant reduction of the circumference of the arm 15 and 20 cm proximal of the lateral epicondyle 24 h after surgery (cold compression: p = 0.003; p < 0.001; cold: p < 0.001). Pain at rest was significantly reduced with cold compression bandage 24 h after surgery (p = 0.001). Skin temperature increased in both groups 24 h after surgery (bandage: p < 0.001; cold pack: p = 0.002). After 24 h, pain during activity was significantly decreased in the group wearing the bandage compared with the group using the cold pack (p = 0.026). CONCLUSIONS: Based on the results of this study, no recommendation can be made with respect to the question whether cold compression therapy or cold therapy should be preferred immediately after arthroscopic surgery of the shoulder. Clinicians should question the need of expensive cold compression bandages in the short-term post-operative treatment after arthroscopic surgery of the shoulder. LEVEL OF EVIDENCE: II.

Differences in acromial morphology of shoulders in patients with degenerative and traumatic supraspinatus tendon tears.

PURPOSE: Distinct characteristics of acromial morphology seem to be one factor for the development of degenerative supraspinatus tendon tears. Thus, it is questionable whether patients with traumatic tendon tears also present these parameters. The hypothesis of the present study was that the acromial morphology of patients with degenerative supraspinatus tendon tears differs from patients with traumatic tears. METHODS: One hundred and thirty-six patients that were treated by arthroscopic rotator cuff repair from 2010 to 2013 were included in this study. Seventy-two patients had degenerative (group 1), and 64 had traumatic (group 2) supraspinatus tendon tears. On preoperative radiographs the Bigliani type, acromial slope, acromiohumeral (AH) distance, lateral acromial angle (LAA), acromion index (AI), and critical shoulder angle (CSA) were measured. Medians of these parameters as well as of age of both groups were compared using the t test. RESULTS: The percentaged distribution of the Bigliani type differed (group 1 vs. 2: type 1: 18/38, type 2: 56/55, type 3: 26/8). All parameters showed significant differences between degenerative and traumatic tears. Slope: 21.2° (SD 7.6°) versus 19.2° (SD 7.9°, p = 0.026), AH distance: 8.4 mm (SD 2.3 mm) versus 9.9 mm (SD 1.9 mm, p = 0.0006), LAA: 77.0° (SD 4.0°) versus 82.5° (SD 4.7°, p < 0.0001), AI: 0.77 (SD 0.07) versus 0.73 (0.06, p = 0.0239), and CSA: 36.8° (SD 3.6°) versus 35.3° (SD 2.9°, p = 0.007). An LAA <70° or an AH distance of <5 mm only occurred in degenerative tears. Patients with degenerative tears were significantly older (60 vs. 54 years). CONCLUSIONS: The hypothesis that the acromial morphology of patients with degenerative supraspinatus tendon tears differs from patients with traumatic tears was confirmed. Shoulders with degenerative tears show a narrower subacromial space and a larger lateral extension as well as a steeper angulation of the acromion than with traumatic tears. Thus, the results of this study support the theory of external impingement as a cause for degenerative rotator cuff tears. LEVEL OF EVIDENCE: IV.

In vivo blood flow after rotator cuff reconstruction in a sheep model: comparison of single versus double row.

PURPOSE: Arthroscopic double-row (DR) suture anchor repair of rotator cuff tears has been shown to be superior to most single-row (SR) techniques with regard to footprint reconstruction, load to failure and tendon-to-bone contact pressures. The hypothesis of this study was that the greater contact pressures of DR techniques would compromise blood flow to a higher degree than SR repair. The aim of this experimental study was to evaluate the effect of a DR and a SR technique on tendon blood flow in a sheep model. METHODS: Eighteen sheep underwent detachment and immediate repair of the infraspinatus tendon using either a Mason-Allen or a suture-bridge technique. Tendon blood flow was measured using laser Doppler flowmetry before detachment, immediately after repair and 12 weeks thereafter. Six regions of interest were measured, three over the lateral and three over the medial aspect of the footprint. RESULTS: Immediately after repair, tendon blood flow decreased significantly in both repair groups (P = 0.004). In the SR group, blood flow decreased by 100.1 arbitrary units (AU) (83.6 %) after repair, in the DR by 81.4 AU (90.5 %). Subgroup analysis showed blood flow over the lateral aspect of the footprint decreased by 126.3 AU (92.2 %) in the SR and 84.4 AU (90.9 %) in the DR group, whereas over the medial aspect, it decreased by 73.9 AU (72.0 %) in the SR and 78.5 AU (90.1 %) in the DR group. None of the differences between the groups were significant. At 12 weeks, measured blood flow in the DR group had increased to 90.1 AU (100.2 %) compared to the native tendons and was at 72.5 AU (60.5 %) for the SR group. Again, the difference between SR and DR group was not statistically significant (n.s.). Assessment for retears showed that 4 of 8 tendons (50 %) in the DR group and 3 of 9 tendons (33.3 %) in the SR group had to be classified as re-ruptures. CONCLUSION: Suture anchor repair leads to an intraoperative decrease in tendon blood flow regardless of the repair technique. A significant difference between SR and DR repair was not found. These findings indicate that tendon blood flow should not be a factor to determine the use of either repair technique over the other.

Acromial morphology in patients with calcific tendinitis of the shoulder.

PURPOSE: The purpose of this study was to evaluate whether the morphology of the acromion in calcific tendinitis differs from controls without subacromial pathology and matches subacromial impingement. METHODS: Digital radiographs of 150 shoulders were evaluated with the open source DICOM-Viewer OsiriX. 50 patients had symptomatic calcific tendinitis of the shoulder, 50 had subacromial impingement without calcifications or rotator cuff tears, 50 with bruised shoulder that were previously asymptomatic served as controls. Acromial shape according to Bigliani et al. acromial tilt (AT) according to Kitay et al. and Aoki et al. acromion index (AI) according to Nyffeler et al. and lateral acromial angle (LAA) according to Banas et al. were measured. RESULTS: Both calcific (0.72; P = 0.001) and impingement groups (0.73; P = 0.008) were significantly different from controls (0.67) using AI measure, while only the calcific group (79.5°) was different from controls (84.1°) using LAA (P < 0.001), and only the impingement group (32.9°) was different from controls (29.2°) using AT (P < 0.001). An LAA <70° only occurred in two patients with calcific tendinitis. CONCLUSION: The hypothesis of this study was that the morphology of the acromion in calcific tendinitis differs from controls without subacromial pathology and matches subacromial impingement was only confirmed for the AI. The AI of shoulders with calcific tendinitis is comparable to that of shoulders with subacromial impingement.

Evaluation of a reconstruction reverse shoulder for tumour surgery and tribological comparision with an anatomical shoulder arthroplasty.

PURPOSE: The functional results after reconstruction of the proximal humerus in tumour surgery are poor. Therefore, a reversed proximal humerus replacement was developed in our institution (MUTARS humerus inverse). A low degree of wear on the polyethylene is required because of the patients' youth and demands on shoulder function. A special type of polyethylene with shock-absorbing properties has been developed to minimise polyethylene wear in the MUTARS inverse proximal humerus replacement. We compared the tribological properties of an anatomical shoulder prosthesis (CAPICA) with the new reversed proximal humerus replacement (MUTARS humerus inverse). METHODS: Both prostheses were tested up to 5 × 10(6) cycles. Every millionth cycle the surface was inspected and a gravimetric measurement was performed. A measurement of surface roughness was done before testing and after 5 × 10(6) cycles. RESULTS: In both prostheses after 5 × 10(6) cycles there were no major defects, such as delamination, observed. In the reversed proximal humerus replacement abrasion of 28 mg/10(6) cycles was detected. The mean abrasion of the anatomical prosthesis was 9.28 mg/ 10(6) cycles. CONCLUSION: The glenoid component of the first reversed humerus replacement (MUTARS humerus inverse) has wear properties comparable to those of normal reversed shoulder prostheses. This is important, as this type of prosthesis is used in young patients after resection of bone tumours, with a good functional outcome. It can, therefore, be expected that the revision rate due to wear will be as high as in patients with normal reversed shoulder prostheses.

Correlation of acromial morphology with impingement syndrome and rotator cuff tears.

BACKGROUND AND PURPOSE: Indications for acromioplasty are based on clinical symptoms and are generally supported by typical changes in acromial morphology on standard radiographs. We evaluated 5 commonly used radiographic parameters of acromial morphology and assessed the association between different radiographic characteristics on the one hand and subacromial impingement or rotator cuff tears on the other. PATIENTS AND METHODS: We measured acromial type (Bigliani), acromial slope (AS), acromial tilt (AT), lateral acromial angle (LAA), and acromion index (AI) on standard radiographs from 50 patients with full-thickness supraspinatus tendon tears, 50 patients with subacromial impingement, and 50 controls without subacromial pathology. RESULTS: The acromial type according to Bigliani was not associated with any particular cuff lesion. A statistically significant difference between controls and impingement patients was found for AS. AT of controls was significantly smaller than that of impingement patients and cuff-tear patients. LAA of cuff-tear patients differed significantly from that of controls and impingement patients, but LAA of controls was not significantly different from that of impingement patients. Differences between impingement patients and cuff-tear patients were also significant. AI of controls was significantly lower than of impingement patients and of cuff-tear patients. A good correlation was found between acromial type and AS. INTERPRETATION: A low lateral acromial angle and a large lateral extension of the acromion were associated with a higher prevalence of impingement and rotator cuff tears. An extremely hooked anterior acromion with a slope of more than 43° and an LAA of less than 70° only occurred in patients with rotator cuff tears.

Subscapularis function after transosseous repair in shoulder arthroplasty: transosseous subscapularis repair in shoulder arthroplasty.

BACKGROUND: Postoperative subscapularis function has been identified as an essential factor influencing the outcome of shoulder arthroplasty. The goal of this study was an evaluation of subjective and objective subscapularis function after transosseous refixation. METHODS: Twenty-three patients with an average age of 71 years (range, 51-86) and follow-up of 43 months (range, 24-67) were included in this study. The subscapularis was tenotomized from the lesser tuberosity and refixation was performed in a transosseous technique through bone tunnels with nonabsorbable sutures. Subscapularis function was evaluated subjectively by the ability to tuck a shirt and objectively with the lift-off test and strength measurement in internal rotation. Radiological assessment included ultrasound evaluation of the subscapularis and an axillary x-ray. RESULTS: No complete, but 7 partial subscapularis tears were found on ultrasound (30.4%). Five patients were not able to tuck their shirt postoperatively (22.7%). This was associated with an inferior clinical outcome (American Shoulder and Elbow Surgeons [ASES] score 53.3 vs 76.4; P = .023). The lift-off test was positive in 4 patients  (17.4%), which was also associated with an inferior clinical result (Constant score 52.3% vs 74.2%; P = .021). Nineteen patients were able to go through an internal rotation strength testing in the lift-off position, and averaged 3.8 kg. CONCLUSION: Although overall reliable refixation of the subscapularis was achieved by transosseous repair, almost 25% of patients showed signs of decreased function and 30% showed signs of partial defects. Subjective and objective functional deficits had a significant influence on the clinical outcome.

Effect of posterior offset humeral components on range of motion in reverse shoulder arthroplasty.

The purpose of this study was to evaluate the effect of eccentric humeral components with different degrees of posterior offset on range of glenohumeral motion in reverse shoulder arthroplasty. Uncemented PROMOS® reverse shoulder prostheses were implanted in eight human cadaveric shoulder specimens. Passive range of motion was evaluated with a robot-assisted shoulder simulator. Three movements were tested: abduction, anterior elevation and external rotation. Each specimen was tested with a customary reverse humeral component and two eccentric components with 3 and 6 mm of posterior offset respectively. Mean abduction was 81° (standard deviation [SD] 12) for the customary reverse components, 81° (SD 13) for the 3 mm eccentric and 82° (SD 15) for 6-mm eccentric implants. Mean anterior elevation was 68° (SD 13) in the regular group and 66° (SD 14) and 63° (SD 14) for 3- and 6-mm eccentric groups. With all configurations, 90° of external rotation were achieved without requiring more than 2 N·m of applied rotational moment. Although there was no statistically significant difference between the conventional and the eccentric implants, anterior elevation was decreased by almost 20° in three of eight shoulders with the posterior offset configurations. This was due to a conflict between the proximal humerus and the anterior aspect of the acromion or the coracoid. Although eccentric humeral components can be useful in reverse shoulder arthroplasty to avoid anterior cortical defects in individuals with pronounced humeral head posterior offset, a potential conflict between proximal humerus and scapula may have an unfavourable effect on range of anterior elevation. However, this observation is only true for the uncemented PROMOS® reverse prosthesis. Other reverse shoulder designs with posterior offset components are yet to be tested.

Prevalence of Musculoskeletal Diseases of the Upper Extremity Among Dental Professionals in Germany.

OBJECTIVE: Although many findings on occupational musculoskeletal complaints are available from American and European dentists, the corresponding data from Germany are still scarce. Therefore, the aim of this study was to provide additional information on the prevalence of and risk factors for musculoskeletal disorders of the upper extremity, particularly the shoulder in this specific population. METHODS: A written survey was carried out among 600 dentists in the state of North Rhine-Westphalia, Germany. Questionnaire items included physical and psychosocial workload, general health, and the occurrence of musculoskeletal symptoms during the previous 12 months that led to sick leave and medical care according to a modified version of the Nordic Musculoskeletal Questionnaire (NMQ). Regression analysis was used to evaluate relevant risk factors for severe musculoskeletal disorders. RESULTS: A total of 229 dentists were participated in the study (response rate 38%). Overall, 92.6% of the participants had already suffered from musculoskeletal symptoms in at least one body region. Symptoms were mostly reported in the neck (65.1%) and in the shoulder (58.1%). Limitations in daily activities were experienced by 15.9% due to neck pain and by 15.4% due to shoulder pain. Medical care was sought by 23.7% because of neck pain and by 21.1% due to shoulder pain. Risk factors for symptoms in the upper extremity regions were gender (female), increased physical load, and numerous comorbidities. CONCLUSION: There is a high prevalence of musculoskeletal disorders among dentists. Suitable interventions are therefore needed to prevent musculoskeletal diseases and pain among dental professionals, with particular attention to female dentists.

Clinical Outcome of Two-Stage Revision after Periprosthetic Shoulder Infection.

BACKGROUND: Periprosthetic shoulder infections are devastating complications after shoulder arthroplasty. A potential treatment concept is a two-stage prosthesis exchange. Data are sparse in terms of clinical outcome, including infection-free survival and patient satisfaction after this procedure. In the present study, we investigated recurrence of infection, revision-free survivorship and clinical outcome following two-stage revision due to periprosthetic shoulder infection. Furthermore, reasons for poor outcome were analyzed. METHODS: Sixteen patients undergoing two-stage revision after shoulder joint infection were retrospectively identified. Recurrence of infection was analyzed by Kaplan-Meier survival curve. Clinical outcome was quantified with subjective shoulder value (SSV), "quick" Disabilities of the Arm, Shoulder and Hand (qDASH) and Rowe score. Range of motion (ROM) was measured pre- and postoperatively. Postoperative scores and ROM were compared in a subgroup analysis according to different reimplanted prosthesis types. RESULTS: The reinfection-free implant survival was 81% after one year and at final follow-up (FU; mean of 33.2 months). The overall revision-free survival amounted to 56% after one year and at final FU. Patients who received reverse shoulder arthroplasty (RSA) as part of reimplantation had less disability and long-term complications. This group demonstrated better subjective stability and function compared to patients revised to megaprostheses or large-head hemiarthroplasties. CONCLUSIONS: Two-stage revision following periprosthetic joint infection of the shoulder allows appropriate infection control in the majority of patients. However, the overall complications and revision rates due to mechanical failure or reinfection are high. Reimplantation of RSA seem superior to alternative prosthesis models in terms of function and patient satisfaction. Therefore, bone-saving surgery and reconstruction of the glenoid may increase the likelihood of reimplantation of RSA and potentially improve outcome in the case of infection-related two-stage revision of the shoulder.

Step activity monitoring in lumbar stenosis patients undergoing decompressive surgery.

Symptomatic degenerative central lumbar spinal stenosis (LSS) is a frequent indication for decompressive spinal surgery, to reduce spinal claudication. No data are as yet available on the effect of surgery on the level of activity measured with objective long-term monitoring. The aim of this prospective, controlled study was to objectively quantify the level of activity in central LSS patients before and after surgery, using a continuous measurement device. The objective data were correlated with subjective clinical results and the radiographic degree of stenosis. Forty-seven patients with central LSS and typical spinal claudication scheduled for surgery were included. The level of activity (number of gait cycles) was quantified for 7 consecutive days using the StepWatch Activity Monitor (SAM). Visual analogue scales (VAS) for back and leg pain, Oswestry disability index and Roland-Morris score were used to assess the patients' clinical status. The patients were investigated before surgery and 3 and 12 months after surgery. In addition, the radiographic extent of central LSS was measured digitally on preoperative magnetic resonance imaging or computed tomography. The following results were found preoperatively: 3,578 gait cycles/day, VAS for back pain 5.7 and for leg pain 6.5. Three months after surgery, the patients showed improvement: 4,145 gait cycles/day, VAS for back pain 4.0 and for leg pain 3.0. Twelve months after surgery, the improvement continued: 4,335 gait cycles/day, VAS for back pain 4.1 and for leg pain 3.3. The clinical results and SAM results showed significant improvement when preoperative data were compared with data 3 and 12 months after surgery. The results 12 months after surgery did not differ significantly from those 3 months after surgery. The level of activity correlated significantly with the degree of leg pain. The mean cross-sectional area of the spinal canal at the central LSS was 94 mm(2). The radiographic results did not correlate either with objective SAM results or with clinical outcome parameters. In conclusion, this study is the first to present objective data on continuous activity monitoring/measurements in patients with central LSS. The SAM could be an adequate tool for performing these measurements in spine patients. Except for leg pain, the objective SAM results did not correlate with the clinical results or with the radiographic extent of central LSS.

Skills in Open Surgery do not Predict Arthroscopic Skills in Medical Students.

OBJECTIVE: Teaching of basic open surgical skills like skin closure has been well established in medical schools' surgical curricula. The same cannot be said for basic arthroscopic skills even though the importance of arthroscopic surgery in Orthopaedics has been well documented. The goal of this study was to evaluate the relationship between basic skills in open surgery and basic arthroscopic skills in a cohort of medical students. Our hypothesis was that performance in open surgical skills does not correlate with skills in arthroscopic surgery. DESIGN: The performance of medical students in basic tasks in open surgery (porcine model: subcutaneous and skin suturing) and arthroscopic surgery (bench top model: arthroscopic triangulation and object transfer) was assessed. For both surgical techniques an introductory course was given followed by a standardized assessment. After 1 week both open and arthroscopic tasks were reassessed. All procedures were recorded and scored by 2 independent observers in a blinded fashion. SETTING: The study was performed at the skills lab of the Clinic for Orthopaedics and Tumororthopaedics at University Hospital Muenster in Muenster Germany. PARTICIPANTS: A cohort of 21 medical students (average age 22.2 years) participated in this study. The cohort consisted of 17 female (81%) and 4 male (19%) students. All students were in the clinical part of their study and had not received any prior surgical education. RESULTS: Interobserver reliability was very high for the arthroscopic tasks and high for the open surgery tasks. No correlation was found between open and arthroscopic skills. For the first assessment the correlation coefficient was r = 0.197 (p = 0.391). For the second assessment the correlation coefficient was r = 0.212 (p = 0.356). Significant improvement from first to second assessment was only found for the arthroscopic tasks (p < 0.0001) while improvement in the open surgery performance failed to reach statistical significance (p = 0.184). CONCLUSIONS: The results of this study suggest that performance in open surgical skills does not correlate with performance in arthroscopic skills and should be taught independent from each other. Arthroscopic skills can effectively be taught with bench top training systems in a time- and resource efficient manner, with measurable results even in a 1-day-course setup. Arthroscopic skills training may be offered in undergraduate curricula in addition to open surgical skills training to students with an interest in Orthopaedics.