Influence of humeral position of the Affinis short® stemless shoulder arthroplasty system on long-term survival and clinical outcome.

BACKGROUND: The purpose of this study was to evaluate the influence of humeral position of Affinis short implant in stemless anatomic total shoulder arthroplasties (STSA) on clinical and radiological results and mid- to long-term survival in the treatment of primary osteoarthritis (OA) of the shoulder. METHODS: 80 patients treated with a stemless shoulder arthroplasty for OA of the shoulder were evaluated with a mean follow-up (FU) of 92 ± 14 months (range 69 to 116 months) by Constant (CS)-Score, Disability of Shoulder, Arm and Hand (DASH)-Score and active range of motion (ROM). Radiographic assessment for bone adaptations and humeral implant position was performed by plain X-rays. Determination of pre- and postoperative center of rotation (COR) was used to assess the restoration of the geometry of the humeral head. The appraisal of proper humeral component positioning was correlated with the functional outcomes. A Kaplan-Meier analysis was calculated, investigating the influence of humeral implant position compared to survival time. Complications were noted. RESULTS: The ROM (p < 0.001), CS-Score (p < 0.001) and DASH-Score (p < 0.001) showed significant improvements after surgery for the entire series. The COR restoration was anatomical in 75 % (n = 60) of all implants and in 25 % (n = 20) non-anatomical (pre- and postoperative COR deviation of 2.7 ± 1.8 mm vs. 5.1 ± 3.2 mm, p = 0.0380). The humeral component position did not affect the functional outcome whereas the ten-year unadjusted cumulative survival rate for the anatomic group was significant higher in comparison with the non-anatomical group (96.7 % vs. 75 %, p = 0.002). The radiological evaluation revealed minor periprosthetic bone adaptions in various forms without clinical significance or further intervention. No revision was necessary due to a failed fixation of the stemless humeral component. CONCLUSIONS: Regarding primary OA of the shoulder, STSA derives excellent long-term survival and clinical outcome. These types of implants are able to restore the geometry of the humeral head. Non-anatomical reconstruction may influence the survival over a long-term period on different pathways. Further studies are necessary to elucidate the effect of humeral component position in STSA on functionality, pain and implant survival rate.

Injection of autologous conditioned plasma combined with a collagen scaffold may improve the clinical outcome in shoulder impingement syndrome: a prospective study.

BACKGROUND: Shoulder impingement syndrome (SIS) is one of the most common diseases of the shoulder and can be addressed with various therapeutic concepts. Orthobiological agents such as platelet rich plasma with a low side effect rate gain importance in the conservative treatment of SIS. Currently, the knowledge about success rate influencing factors, such as the growth factors (GF) concentration or acromion type, is limited. The aim of this study was to analyze the clinical outcome in the therapy of external SIS using autologous conditioned plasma combined with recombinant human collagen scaffold (ACP/STR) injection in comparison with a corticosteroid-local anesthetic (CSA) injection. Additionally, the influence of potential limiting factors such as GF concentration, age and acromial morphology was proved. MATERIALS AND METHODS: This prospective pseudo-randomized trial recruited 58 patients with external SIS who received an ultrasound-guided subacromial injection either an ACP/STR or a CSA followed by physical therapy. Follow-up (FU) was performed at 6 weeks, 3 and 6 months. The outcome was assessed with Constant-Murley score, disability of arm, shoulder and hand score and simple shoulder test. The concentration of GF was measured using ELISA. RESULTS: During the FU, the improvement of outcome measures was observed with no differences between both groups. Shoulder force was significantly increased in the ACP/STR group (p < 0.01). We found no correlation between the amount of GF and age or gender in the ACP/STR patients. An acromion Bigliani type III predisposes for therapy failure (p < 0.001, OR = 56) in both treatment groups. CONCLUSIONS: Patients with SIS benefit regarding to PROMs after both ACP/STR and CSA injection and physical therapy. Patients who received ACP/STR obtained superior improvement in force. The quantity of GF did not vary depending on the age, so that ACP/STR can be a treatment option for SIS in elderly patients with multimorbidity. The presence of an acromion type III seems to be a predictive factor for limited effectivity of injections in the clinical management of SIS.

The Unhappy Shoulder: A Conceptual Review of the Psychosomatics of Shoulder Pain.

INTRODUCTION: Chronic pain is a multifaceted disorder genuinely entangled with psychic and psychosomatic symptoms, which are typically involved in the processes of chronification. The impingement syndrome of the shoulder is no exception to this rule, but several studies have shown respective peculiarities among those with pain and impingement of the shoulder. Notably, chronic pain is a lateralized experience, and, similarly, its psychosomatic correlates may be attached to the hemispheres functionally. AIM: The present review therefore gives an overview of the respective findings, with regard not only to psychopathology, but also to personality factors and psychologic trauma, since the latter are reportedly associated with chronic pain. Moreover, we acknowledge symmetry as a possible pathogenic factor. METHODS: This narrative review followed the current standards for conducting narrative studies. Based on prior findings, our research strategy included the relevance of psychotraumatologic and symmetrical aspects, as well as comorbidity. We retrieved the relevant literature reporting on the impact of psychopathology as well as personality features on shoulder pain, as published up to January 2022 from the Medline database (1966-2022). Study selecton: We included numerous studies, and considered the contextual relevance of studies referring to the neuropsychosomatics of chronic pain. RESULTS: Pain-specific fears, depression, and anxiety are important predictors of shoulder pain, and the latter is generally overrepresented in those with trauma and PTSD. Moreover, associations of shoulder pain with psychological variables are stronger as regards surgical therapies as compared to conservative ones. This may point to a specific and possibly trauma-related vulnerability for perioperative maladaptation. Additionally, functional hemispheric lateralization may explain some of those results given that limb pain is a naturally lateralized experience. Not least, psychosocial risk factors are shared between shoulder pain and its physical comorbidities (e.g., hypertension), and the incapacitated state of the shoulder is a massive threat to the function of the human body as a whole. CONCLUSIONS: This review suggests the involvement of psychosomatic and psychotraumatologic factors in shoulder impingement-related chronic pain, but the inconclusiveness and heterogeneity of the literature in the field is possibly suggestive of other determinants such as laterality.

Radiological changes in shoulder osteoarthritis and pain sensation correlate with patients' age.

PURPOSE: Osteoarthritis (OA) is one of the most common musculoskeletal disorders in the aging population. The correlation of radiographic OA severity, disability and pain is variable and inconsistent for the different joints. This study aims to elucidate the relationship between histological and radiological signs of shoulder OA with pain sensation and functional impairment to potentially adapt the recommendation for surgical treatment for primary total shoulder arthroplasty (TSA). METHODS: Forty-four patients with shoulder OA undergoing TSA using an anatomic stemless implant were included in this study. The radiological OA severity was scored pre-operatively on true ap X-rays according to the Kellgren-Lawrence score (KL-Score). Acromial types according to Bigliani were defined by pre-operative radiological images. The histological OA severity was determined according to the OARSI-Score using bone-cartilage sections from loaded areas of the humeral head. Pain was quantified using the visual analog scale (VAS). The functional status was assessed by the items "mobility" and "strength" out of the Constant-Murley score (CS Score). Demographic data including BMI, age, gender, diabetes mellitus and smoking were recorded. RESULTS: There was no correlation between radiographic and histological severity in shoulder OA. However, a correlation of age and the severity of radiological changes was observed. Further, pain did not correlate with histological or radiological scores, whereas it correlated with age and the presence of diabetes mellitus. The functional shoulder status (mobility, strength) correlated with the severity of radiological changes, but not with the histologic scoring, which correlated with nicotine abuse. CONCLUSION: This study shows that increased age is the main determinant of radiological changes in shoulder OA, as well as pain. Therefore, age and pain sensation should be considered as important parameters for the recommendation for TSA.

Are Anxiety and Depression Taking Sides with Knee-Pain in Osteoarthritis?

INTRODUCTION: Total knee arthroplasty (TKA) bears a potential of rendering patients unsatisfied with the operation as a result of negative affectivity related to osteoarthritis and TKA. Not only is pain a lateralized experience, but negative affect and other psychosomatic correlates of pain might also be processed on grounds of lateralization. Lateralization in this context is likely linked to the amygdalae, which display differential left/right patterns of association with psychopathology. What is noteworthy is that osteoarthritis itself is linked not only to negative effects but also to childhood abuse. METHOD: The present study tests lateralization of psychosomatic correlates of knee-pain using the brief symptom inventory-18 (BSI-18), the dissociative experiences scale (FDS-20), the pain catastrophizing scale (PCS), the Tampa scale of kinesiophobia (TSK), the childhood trauma screener (CTS) and WOMAC. More precisely, we were interested in predicting the side of operations by means of the above-mentioned constructs using binary logistic regression, based on 150 participants (78 left knees) awaiting TKA for knee-osteoarthritis. RESULTS: Somatization (p = 0.003), childhood abuse (p = 0.04) and pain-catastrophizing (p = 0.04) predicted operations on the right side. Anxiety (p = 0.001) and kinesiophobia (p = 0.002) predicted operations on the left side. CONCLUSIONS: Knee-pain may be differentially modulated by its psychosomatic correlates as a result of lateralization and corresponding patterns of psychosomatic reagibility.

Long-term survival and failure analysis of anatomical stemmed and stemless shoulder arthroplasties.

AIMS: The purpose of this study was to compare clinical results, long-term survival, and complication rates of stemless shoulder prosthesis with stemmed anatomical shoulder prostheses for treatment of osteoarthritis and to analyze radiological bone changes around the implants during follow-up. METHODS: A total of 161 patients treated with either a stemmed or a stemless shoulder arthroplasty for primary osteoarthritis of the shoulder were evaluated with a mean follow-up of 118 months (102 to 158). The Constant score (CS), the Disabilities of the Arm, Shoulder and Hand (DASH) score, and active range of motion (ROM) were recorded. Radiological analysis for bone adaptations was performed by plain radiographs. A Kaplan-Meier survivorship analysis was calculated and complications were noted. RESULTS: The ROM (p < 0.001), CS (p < 0.001), and DASH score (p < 0.001) showed significant improvements after shoulder arthroplasty for both implants. There were no differences between the groups treated with stemmed or stemless shoulder prosthesis with respect to the mean CS (79.2 (35 to 118) vs 74.4 (31 to 99); p = 0.519) and DASH scores (11.4 (8 to 29) vs 13.2 (7 to 23); p = 0.210). The ten-year unadjusted cumulative survival rate was 95.3% for the stemmed anatomical shoulder prosthesis and 91.5% for the stemless shoulder prosthesis and did not differ between the treatment groups (p = 0.251). The radiological evaluation of the humeral components in both groups did not show loosening of the humeral implant. The main reason for revision for each type of arthroplasties were complications related to the glenoid. CONCLUSION: The use of anatomical stemless shoulder prosthesis yielded good and reliable results and did not differ from anatomical stemmed shoulder prosthesis over a mean period of ten years. The differences in periprosthetic humeral bone adaptations between both implants have no clinical impact during the follow-up. Cite this article: Bone Joint J 2021;103-B(7):1292-1300.

Intraoperative assembly of anatomical shoulder prosthesis frequently results in malalignment of the modular taper junction.

Anatomical shoulder arthroplasties (ASA) may fail because of micromotion at the modular taper junction causing wear due to fretting. Sufficient taper strength can reduce micromotion and potential reasons for failure. However, there are no normative standards for a safe assembly process performed intraoperatively by the surgeon. The purpose of this study is to determine the effect of common intraoperative assembly strategies and to identify critical influencing factors on taper stability. ASA with standard and stemless humeral component in combination with concentric Al2 O3 heads and eccentric CoCr28Mo6 alloyed humeral heads were tested. Taper angles and surface roughness were determined. Force magnitudes and impact directions were recorded using a sensorized head impactor and a three-dimensional force measuring platform. Subsequently, the axial pull-off forces were measured and taper engagement areas were macroscopically evaluated. In comparison to standard stem tapers that were impacted with an assembly device, stemless tapers were impacted into the artificial bone with significantly lower forces. Taper strength correlates to maximum impact force and was higher for CoCr28Mo6 heads with a mean pull-off ratio of 0.56 than for Al2 O3 heads with 0.37. Interestingly, all tapers showed an asymmetric clamping behavior, due to tilting during impaction. This is caused by the variation of the resulting force vector and further promoted by humeral head eccentricity. Assembly technique markedly influences the force magnitude, impact direction, impulse, and consequently taper strength. The resulting force vector and head eccentricity were identified as potential risk factors for taper malalignment.

In vivo corrosion and damages in modular shoulder prostheses.

Wear and corrosion at taper junctions of orthopaedic endoprostheses remain of great concern and are associated with adverse clinical reactions. Whereas tribocorrosion of hip tapers was extensively investigated, there is only little knowledge regarding the clinical performance of modular total shoulder prostheses. This retrieval study evaluated 35 modular taper junctions of anatomical shoulder explants using stereomicroscopy, confocal microscopy, as well as optical and scanning electron microscopy to determine the damage modes as well as the effects of taper topography and alloy microstructure. Among all humeral head tapers, 89% exhibited material degradation. Different overlapping wear mechanisms were identified such as plastic deformation, adhesive material transfer, microploughing, and fretting damage. Only CoCrMo cast alloy heads showed a susceptibility to electrochemically dominated fretting in comparison to CoCrMo wrought alloy. Moreover, corundum blasted stem tapers show a significantly increased incidence rate for microploughing. To date, this is the most comprehensive study on the damage types of modular taper junctions of anatomical shoulder arthroplasty proving the existence of fretting even on less weight-bearing implants. This study revealed critical fretting factors, such as the surface finish and the alloy type that are essential for the development of countermeasures that avoid any taper corrosion.

Magnetic resonance-guided direct shoulder arthrography for the detection of superior labrum anterior-posterior lesions using an open 1.0-T MRI scanner.

PURPOSE: Direct magnetic resonance arthrography (MRA) offers increased diagnostic accuracy compared to conventional magnetic resonance imaging (MRI) in the detection of superior labrum anterior-posterior (SLAP) lesions. The aim of the present study was to present the technique of magnetic resonance-guided direct shoulder arthrography (MDSA), to evaluate the diagnostic value of this novel MRA procedure to detect SLAP lesions in comparison to the currently practiced MRI, and to correlate the radiological findings to the respective arthroscopic findings. MATERIAL AND METHODS: Fifty-six patients with clinical signs of a SLAP lesion underwent both MRI examination and MDSA prior to arthroscopic surgery. The MRI of both interventions were compared with the arthroscopic findings. Statistical analysis was performed using the McNemar test. RESULTS: Sensitivity, specificity, and accuracy for detecting SLAP lesions were 23%, 88%, and 54% on MRI and 80%, 81%, and 80% on MDSA, respectively. Sensitivity (p < 0.001) and accuracy (p = 0.001) in detection of SLAP lesions were significantly higher by MDSA whereas accuracy showed no significant differences (p = 0.625). CONCLUSIONS: The MDSA can be performed in an open 1.0-T MRI scanner with a high level of technical success and a reasonable methodical effort. The modification of MRA provides the requirements as a practicable routine shoulder magnetic resonance examination including arthrography to detect SLAP lesions. The diagnostic value is significantly better than MRI examinations without included arthrography, which currently predominates the clinical practice to investigate shoulder pathology.

Adjustable stemmed shoulder hemiarthroplasty: Ten-year results of a prospective multicentre study.

BACKGROUND: Adjustable shoulder hemiarthroplasty (HA) allows the complex anatomy of the proximal humerus, including its centre of rotation, to be restored. However, whether better anatomical adaptation improves clinical outcomes and long-term survival remains unclear. Therefore long-term clinical and radiographic results of an eccentric adjustable hemiprosthesis were examined, focusing on the longevity and fixation of the humeral stem. HYPOTHESIS: Adjustable shoulder HA enhances long-term functional outcomes and reduces complications. MATERIALS AND METHODS: In this prospective multicentre study, 120 HAs were performed using a stemmed hemiprosthesis on 115 patients. The clinical and radiologic outcomes were measured at 3, 6, 12, and 24 months, and thereafter at 4, 7, and 10 years with a median follow-up period of 7.7 years (92.3 months, range 2.6-148.5 months). Revision-free survival rates were calculated up to 10 years postoperatively. RESULTS: The mean Constant-Murley score increased over the first 24 months from 26.2±9.0 to 61.0±17.3 points, then levelled off until the final follow-up. Patients with humeral head necrosis had the best clinical outcomes, while patients with fracture sequelae and rheumatoid arthritis had the worst. Although radiolucent lines were more frequent after cemented fixation, lines of>2mm only occurred after uncemented fixation. Finally, five cases required secondary glenoid implantation, and survival free from stem revision was 99.0% (95% confidence interval [CI], 92.8%-99.9%) at 4 years, 97.6 (95% CI, 90.6%-99.4%) at 7 years, and 92.2% (95% CI, 81.9%-96.8%) at 10 years. DISCUSSION: The study showed that adjustable shoulder HA is a safe and effective treatment option for various degenerative disorders of the shoulder joint. Functional scores first increased, then levelled off after 24 months. Moreover, revision-free survival compared well with previously reported values. Observed stable long-term results confirm that adjustable shoulder HA has beneficial clinical outcomes and a low complication rate.

The terminal complement pathway is activated in septic but not in aseptic shoulder revision arthroplasties.

BACKGROUND: The early diagnosis of suspected periprosthetic low-grade infections in shoulder arthroplasties is important for the outcome of the revision surgical procedures. The aim of this study was to investigate new biomarkers of infection in revision shoulder arthroplasties, taking into account the implant design, patient age, and comorbidities. METHODS: The study included 33 patients with shoulder arthroplasties undergoing revision surgical procedures. Microbiological diagnostic testing was performed in all cases. C-reactive protein serum levels and white blood cell counts were evaluated, and the periprosthetic tissue was stained immunohistologically for the terminal complement pathway components (C3, C5, and C9) and for CD68 and α-defensin. RESULTS: Microbiological diagnostic testing detected a periprosthetic infection in 10 reverse shoulder arthroplasties and in 4 anatomic shoulder arthroplasties, while the remaining 19 shoulder arthroplasties were classified as aseptic. We observed more Staphylococcus epidermidis infections in reverse shoulder arthroplasties and more Staphylococcus aureus infections in anatomic shoulder arthroplasties. The revision rate correlated with pre-existing comorbidities and number of previous surgical procedures. The C-reactive protein values and the incidence of specific periprosthetic radiolucent lines were significantly increased in septic revision cases. We found increased staining for all tested complement factors (C3, C5, and C9) but not for α-defensin and CD68 in septic tissue. The most interesting finding was that C9 separated septic from aseptic tissue with a predictive specificity of 100% and a sensitivity of 88.89%. CONCLUSION: We observed a strong correlation between C9 expressions in septic revision tissue. We propose that the terminal complement pathway, especially C9 deposition, may be a potential biomarker to identify septic complications using tissue biopsy specimens.

SPECT/CT demonstrates the osseointegrative response of a stemless shoulder prosthesis.

BACKGROUND: This study evaluates bone remodeling processes in the proximal humerus induced by the implantation of a stemless shoulder prosthesis with regard to time of response and type and extent of bone turnover. METHODS: Twenty-eight patients with primary osteoarthritis of the shoulder undergoing a stemless shoulder arthroplasty were prospectively evaluated. The local metabolic bone activity in 5 regions of interest (ROIs 1-5) around the implant and in 1 reference region (ROI ref.) in the humeral diaphysis was analyzed after the application of technetium Tc 99m DPD using single-photon emission computed tomography integrated with multidetector computed tomography (SPECT/CT). The study cohort was divided into 4 groups according to the timing of the most recent follow-up appointment to evaluate the primary osseointegrative response after surgery. The bone uptake values were expressed in target (ROIs 1-5) to nontarget (ROI ref.) ratios. RESULTS: No difference within the 4 subgroups with respect to the time of local metabolic bone activity in the ROIs was found at 90 days after surgery. The highest initial metabolic activity and most temporal modifications were found in ROI 1, which was localized in the superior segment of the stem. CONCLUSIONS: SPECT/CT data suggest that the primary osseointegration of a stemless shoulder prosthesis is almost completed 3 months after implantation. Variations in metabolic activity pattern in the ROIs during follow-up may be caused by different loading conditions of the bone.

Glenoid morphology affects the incidence of radiolucent lines around cemented pegged polyethylene glenoid components.

PURPOSE: Radiolucent lines (RLL) are frequent findings around cemented all-polyethylene glenoid implants. The present study evaluates the frequency, extend and the clinical impact of RLL around a cemented two-pegged glenoid implant with special focus on the influence of preoperative glenoid morphology. Our hypothesis was that glenoid morphology does not affect clinical outcome and RLL in the investigated setting. METHODS: Between 2003 and 2008, a total of 113 cases of total shoulder arthroplasties (Affinis, Mathys Ltd Bettlach, Switzerland) were performed in three surgical centres using a pegged cemented polyethylene glenoid component. A total of 90 cases could be evaluated clinically and radiographically. Clinical outcome was analysed using the constant score (CS) and range of motion assessment. Radiographic evaluation was performed in true anterior-posterior and axial views with special focus on loosening and RLL. Further, preoperative glenoid morphology was documented and its correlation to radiolucent lines and clinical outcomes was evaluated. RESULTS: At a mean of 58.8 (range 31.2-92.5)-month follow-up the CS improved from 21.5 points preoperatively to 62.3 points postoperatively. Radiolucent lines were found in 76.6 % of cases. If present, RLL were located at the backside of the implant (74.4 %) in the majority of the cases not around the pegs (10 %). There was no significant correlation between RLL and clinical outcome or follow-up time. The amount and extend of RLL were correlated to glenoid morphology with significantly higher values for glenoid types B2 and C according to Walch in comparison to glenoid types A1, A2 and B1. CONCLUSIONS: RLL did not affect clinical outcome and did not correlate with the follow-up time. Patients with glenoid morphology types B2 and C showed significantly worse radiographic results. LEVEL OF EVIDENCE: Level IV case series study.

Stemless shoulder prosthesis versus conventional anatomic shoulder prosthesis in patients with osteoarthritis: a comparison of the functional outcome after a minimum of two years follow-up.

BACKGROUND: The stemless shoulder prosthesis is a new concept in shoulder arthroplasty. To date, only a few studies have investigated the results of this prosthesis. The aim of this study was to investigate the clinical and radiological midterm results of this implant in comparison with a standard anatomic stemmed shoulder prosthesis. MATERIALS AND METHODS: The Constant score, the DASH score, the active range of motion (abduction, anteversion, external rotation), and the radiological results were examined in 82 patients with primary osteoarthritis of the shoulder treated with either the Total Evolutive Shoulder System(®) (Biomed, France) stemless shoulder prosthesis or the Affinis(®) (Mathys, Switzerland) stemmed shoulder prosthesis to detect possible differences in the functional outcome and to evaluate radiological properties of the implants. Patients were examined before and 32 ± 4 months after surgery. RESULTS: There was no significant difference in the Constant scores of the groups treated with the stemless shoulder prosthesis (65.0 ± 11.0 points) and the stemmed shoulder prosthesis (73.2 ± 11.3 points; P = 0.162). The estimated blood loss (P = 0.026) and the mean operative time (P = 0.002) were significantly lower in the group with the stemless shoulder prosthesis. CONCLUSIONS: The use of the stemless shoulder prosthesis yielded good results which, in a mid-term follow-up, were comparable with those provided by a standard anatomic shoulder prosthesis. Further investigations are needed regarding the long-term performance of this prosthesis.

Variability of medial and posterior offset in patients with fourth-generation stemmed shoulder arthroplasty.

PURPOSE: Most anthropometric data on the proximal humerus has been obtained from deceased healthy individuals with no deformities. Endoprostheses are implanted for primary and secondary osteoarthritis, rheumatoid arthritis,humeral-head necrosis, fracture sequelae and other humeral-head deformities. This indicates that pathologicoanatomical variability may be greater than previously assumed. We therefore investigated a group of patients with typical shoulder replacement diagnoses, including posttraumatic and rheumatic deformities. MATERIAL AND METHODS: One hundred and twenty-two patients with a double eccentrically adjustable shaft endoprosthesis served as a specific dimension gauge to determine in vivo the individual humeral-head rotation centres from the position of the adjustable prosthesis taper and the eccentric head. RESULTS: All prosthesis heads were positioned eccentrically.The entire adjustment range of the prosthesis of 12 mm medial/lateral and 6 mm dorsal/ventral was required. Mean values for effective offset were 5.84 mm mediolaterally[standard deviation (SD) 1.95, minimum +2, maximum +11]and 1.71 mm anteroposteriorly (SD 1.71, minimum −3,maximum 3 mm), averaging 5.16 mm (SD 1.76, minimum +2,maximum + 10). The posterior offset averaged 1.85 mm(SD 1.85, minimum −1, maximum + 6 mm). CONCLUSIONS: In summary, variability of the combined medial and dorsal offset of the humeral-head rotational centre determined in patients with typical underlying diagnoses in shoulder replacement was not greater than that recorded in the literature for healthy deceased patients.The range of deviation is substantial and shows the need for an adjustable prosthetic system.

Massive rotator cuff tears: functional outcome after debridement or arthroscopic partial repair.

BACKGROUND: The surgical treatment of massive rotator cuff tears (RCT) is still controversial and can be based on a variety of different surgical repair methods. This study investigated the effectiveness of arthroscopic debridement or arthroscopic partial repair in patients with massive RCT. MATERIALS AND METHODS: This prospective, randomized study involved forty-two patients with massive RCT (fatty infiltration stage 3 or 4) treated with either arthroscopic partial repair or arthroscopic debridement were selected to detect possible differences in functional outcome. Both groups were matched according to age and gender. Patients were examined before, and 16 +/- 3 and 24 +/- 2 months after surgery. The status of the rotator cuff repair was determined using ultrasonographic evaluation. RESULTS: Regardless of the treatment group, postoperative results demonstrated highly significant improvements compared with preoperative values in most parameters. The overall Constant score in the partial repair group was superior to the outcome in the debridement group (P < 0.01, F = 8.561), according to better results in abduction (P < 0.01, F = 13.249), activity (P < 0.01, F = 21.391) and motion (P < 0.01, F = 4.967). All treatment groups had similar pain relief (P = 0.172, F = 1.802) and satisfaction, reflected in equal values of disabilities of the arm, shoulder and hand (DASH) score (P = 0.948, F = 0.004). Ultrasonography revealed structural failure of the partial rotator cuff repair in 52% at final follow-up. CONCLUSIONS: During the follow-up period all patients in our series had good or satisfactory outcome after rotator cuff surgery. Regardless of high rates of structural failure of the partial rotator cuff repair, the results of arthroscopic partial rotator cuff repair demonstrated slightly better functional outcome than debridement.

Altered neuromuscular control of a hand muscle in chronic rotator cuff tears.

INTRODUCTION: Previous EMG studies have shown that chronic rotator cuff tears (RCT) may be associated with an altered activation of adjacent shoulder muscles. The effect of RCT on central neuromuscular control mechanisms of hand muscles has as yet not been studied in detail. This study investigated the cortico-motor excitability of the first dorsal interosseus muscle (FDI) in patients with RCT. MATERIALS AND METHODS: The resting motor threshold (RMT) of the FDI on both sides were obtained from patients with unilateral chronic RCT and compared with healthy control subjects without any shoulder pathologies with transcranial magnetic stimulation. Analysis of variance for repeated measures was performed to detect possible differences in RMT of the FDI in patients and healthy controls. RESULTS: The RMT of FDI in patients on the affected side was lower when compared to the non-affected side (p = 0.015) and to both sides in control subjects (p = 0.041, F = 4.8). CONCLUSIONS: The reduced RMT of FDI in patients with unilateral RCT may be related to alterations in the sensory output from the shoulder and points toward a complete sensimotor restriction of the involved upper limb. These findings seem to be assigned to adaptive changes in the motor cortex as a consequence of chronic RCT.

Anatomic and reverse shoulder prostheses in fracture sequelae of the humeral head.

OBJECTIVES: Arthroplasty for the proximal humerus problems secondary to fractures is troublesome, because of necrosis of the tubercles and the resulting insufficiency of the rotator cuff. The aim of this study was to investigate whether better results can be achieved with the differential use of anatomic and reverse shoulder prostheses, in comparison to the preoperative status. METHODS: Fifty-five patients with secondary fracture prostheses due to sequelae of fractures of the humeral head were followed. Anatomic prostheses were implanted in 36 cases (fracture sequelae types 1 and 2 according to Boileau), and reversed prostheses were implanted in 19 cases (fracture sequelae types 3 and 4). RESULTS: The mean scores of the patients improved from 19 to 68 points (anatomic prosthesis) for fracture sequelae types 1 and 2, and from 9 to 47.5 points (reverse prosthesis) for fracture sequelae types 3 and 4. CONCLUSION: The differential use of anatomic and reversed shoulder prostheses in secondary fracture treatment leads to an improvement in postoperative results. In fracture sequelae types 1 and 2, the anatomic prosthesis is a better choice. However, in fracture sequelae types 3 and 4 with severe deformities, the reversed prosthesis is clearly superior to the anatomic prosthesis.

Central neuromuscular dysfunction of the deltoid muscle in patients with chronic rotator cuff tears.

BACKGROUND: Previous surface electromyogram (EMG) studies have shown that chronic rotator cuff tears (RCT) may be associated with a altered activation of adjacent shoulder muscles. The effect of RCT on central neuromuscular control mechanisms of the shoulder girdle muscles such as the deltoideus muscle (DM), a key muscle of shoulder function, has as not yet been studied in detail. MATERIALS AND METHODS: This study investigated the corticospinal excitability of the DM to assess the effects of RCT on the central neuromuscular function of proximal upper limb muscles. The motor-evoked potentials (MEP) in response to transcranial magnetic stimulation of DM on both sides were obtained from patients with unilateral RCT and compared with healthy control subjects. RESULTS: In patients, stimulus response curves of DM demonstrated a bilateral hyperexcitability at rest and a hypoexcitability during voluntary activation (F = 3.82, P = 0.007). CONCLUSIONS: The DM hyperexcitability may be related to alterations in the sensory output from the shoulder. The insufficient facilitation of the DM points toward a bilateral central activation deficit. These findings seem to be assigned to adaptive changes in the motor cortex as a consequence of chronic RCT, and the neuromuscular alteration of the DM should be considered when treating patients with RCT.

Hemi- versus bipolar shoulder arthroplasty for chronic rotator cuff arthropathy.

Both bipolar and hemiarthroplasty have been used to treat rotator cuff arthropathy (RCA) of the shoulder in patients with low functional demands. In this study, 41 patients treated with either a bipolar or hemiarthroplasty were selected retrospectively to detect possible differences in the functional outcome and to evaluate radiological properties of the implants. Patients were examined before and 30 +/- 6 months after surgery. There were no differences in the Constant scores between the groups treated with hemiarthroplasty and bipolar arthroplasty, 58.9 +/- 13.1 points and 55.8 +/- 13.5 points, respectively (P = 0.457). We found a significant increase in abduction postoperatively in both groups (P = 0.041 bipolar, P = 0.000 hemiarthroplasty) but without statistical significance between the hemiarthroplasty and bipolar arthroplasty groups (P = 0.124, F = 2.6). This result is related in the bipolar group due to movement between the shell and inner head (P = 0.042) and in the hemiarthroplasty group due to movement between the humeral head component and the glenoid (P = 0.000). In conclusion, we found that both hemiarthroplasty and bipolar arthroplasty are effective treatment options for carefully selected patients with RCA and low functional demands, with no differences between the groups.