Impact of polyethylene glenoid cementation technique on cement mantle integrity and stability after cyclic loading: a computed tomography and biomechanical study.

BACKGROUND: There are no generally accepted guidelines for polyethylene (PE) glenoid component cementation techniques. In particular, it is not known whether the backside of a PE glenoid should be fully or partially cemented-or not cemented at all. We hypothesized that cementing techniques would have an impact on cement mantle volume and integrity, as well as biomechanical stability, measured as micromotion under cyclic loading. METHODS: To address our hypothesis, 3 different cementation techniques using a single 2-peg PE glenoid design with polyurethane foam were compared regarding (1) the quality and quantity of the cement mantle and (2) biomechanical stability after cyclic loading in vitro. Eight identically cemented glenoids per group were used. Group A underwent cement application only into the peg holes, group B received additional complete cement mantle application on the backside of the glenoid, and group C received the same treatment as group B but with additional standardized drill holes in the surface of the glenoid bone for extra cement interdigitation. All glenoids underwent cyclic edge loading by 105 cycles according to ASTM F2028-14. Before and after loading, cement mantle evaluation was performed by XtremeCT and biomechanical strength and loosening were evaluated by measuring the relative motion of the implants. RESULTS: The cement mantle at the back of the implant was incomplete in group A as compared with groups B and C, in which the complete PE backside was covered with a homogeneous cement mantle. The cement mantle was thickest in group C, followed by group B (P = .006) and group A (P < .001). We did not detect any breakage of the cement mantle in any of the 3 groups after testing. Primary stability during cyclic loading was similar in all groups after the "running-in" phase (up to 4000 cycles). Gross loosening did not occur in any implant. CONCLUSIONS: Coverage of the PE glenoid with cement was reproducible in the fully cemented groups (ie, groups B and C) as compared with relevant cement defects in group A. The addition of cement to the back of the PE glenoid and additional drill holes in the glenoid surface did not improve primary stability in the tested setting.

Mid-term to long-term results of primary arthroscopic Bankart repair for traumatic anterior shoulder instability: a retrospective study.

BACKGROUND: The arthroscopic method offers a less invasive technique of Bankart repair for traumatic anterior shoulder instability. The aim of the study is to determine the mid-/long-term functional outcome, failure rates and predictors of failure after primary arthroscopic Bankart repair for traumatic anterior shoulder instability. METHODS: A total of 100 patients were primarily operated using arthroscopic Bankart repair after traumatic anterior shoulder instability. Medical records were retrospectively reviewed, and patients were assessed using postal questionnaire after a mean follow-up of 8.3 years [3-14]. Clinical assessment was performed using Constant score, Rowe score, and American Shoulder and Elbow Surgeons score. RESULTS: The overall recurrence rate was 22%. The Kaplan-Meier failure-free survival estimates. were 80% at 5 years and 70% at 10 years. Nearly half (54.5%) of recurrences occurred at 2 years postoperative. Compared with normal shoulder, there were statistical differences in all 3 scores. Failure rate was significantly affected by age at the time of surgery with 86% of recurrence cases observed in patients aged 30 years or younger. Nevertheless, Younger age at the time of surgery (P = 0.007) as well age at the time of initial instability (P = 0.03) was found to correlate negatively with early recurrence within 2 years of surgery. Among those with recurrent instability, recurrence rate was found to be higher if there had been more than 5 instability episodes preoperatively (P = 0.01). Return to the preinjury sport and occupational level was possible in 41 and 78%, respectively. CONCLUSION: Failure-free survival rates dropped dramatically over time. Alternative reconstruction techniques should be considered in those aged ≤30 years due to the high recurrence rate.

Preoperative deltoid assessment by contrast-enhanced ultrasound (CEUS) as predictor for shoulder function after reverse shoulder arthroplasty: a prospective pilot study.

INTRODUCTION: Although the deltoid represents the main motor muscle after reverse shoulder arthroplasty (RSA), its standardized preoperative assessment regarding morphology and function is still not established. Its clinical relevance and interactions with major biomechanical parameters like the medialization of the center of rotation (COR) regarding shoulder function after RSA are yet unknown. We evaluated contrast-enhanced ultrasound (CEUS) of the deltoid as possible surrogate marker for individual deltoid properties of patients receiving an RSA, and its predictive value for postoperative shoulder function. MATERIALS AND METHODS: 35 patients were prospectively assessed. Before and 6 months after RSA, dynamic deltoid perfusion, caliber and a combination of both (PE*caliber, named DeltoidEfficacy) was quantified by CEUS. Changes of deltoid properties and the predictive value of preoperative CEUS-based deltoid properties for shoulder function after RSA were assessed. To analyze interrelating effects with deltoid properties, COR-medialization and deltoid lengthening were quantified. RESULTS: Deltoid caliber and perfusion significantly increased after RSA (p = 0.0004/p = 0.002). Preoperative deltoid caliber, perfusion and the combined value DeltoidEfficacy significantly correlated with shoulder function after RSA within the whole study cohort (caliber: r = 0.445, p = 0.009; perfusion: r = 0.593, p = 0.001; DeltoidEfficacy: r = 0.66; p = 0.0002). The predictive value of DeltoidEfficacy for shoulder function after RSA varied among patient subgroups: Multivariate regression analysis revealed the strongest prediction in patients with either very high or very low deltoid properties (Beta = 0.872, r = 0.84, p = 0.0004), independent from COR-medialization or deltoid lengthening. Contrary, in patients with intermediate deltoid properties, COR-medialization revealed the strongest predictive value for shoulder function after RSA (Beta = 0.660, r = 0.597; p = 0.024). CONCLUSION: Deltoid CEUS seems to allow an assessment of individual deltoid properties and deltoid adaptations after RSA. Deltoid CEUS seems to predict shoulder function after RSA and might support an identification of patients requiring special attention regarding COR positioning.

Diagnostic performance of 3D-multi-Echo-data-image-combination (MEDIC) for evaluating SLAP lesions of the shoulder.

BACKGROUND: Superior labral anterior to posterior (SLAP) lesions remain a clinical and diagnostic challenge in routine (non-arthrographic) MR examinations of the shoulder. This study prospectively evaluated the ability of 3D-Multi-Echo-Data-Image-Combination (MEDIC) compared to that of routine high resolution 2D-proton-density weighted fat-saturated (PD fs) sequence using 3 T-MRI to detect SLAP lesions using arthroscopy as gold standard. METHODS: Seventeen consecutive patients (mean age, 51.6 ± 14.8 years, 11 males) with shoulder pain underwent 3 T MRI including 3D-MEDIC and 2D-PD fs followed by arthroscopy. The presence or absence of SLAP lesions was evaluated using both sequences by two independent raters with 4 and 14 years of experience in musculoskeletal MRI, respectively. During arthroscopy, SLAP lesions were classified according to Snyder's criteria by two certified orthopedic shoulder surgeons. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 3D-MEDIC and 2D-PD fs for detection of SLAP lesions were calculated with reference to arthroscopy as a gold standard. Interreader agreement and sequence correlation were analyzed using Cohen's kappa coefficient. Figure 1 demonstrates the excellent visibility of a proven SLAP lesion using the 3D-MEDIC and Fig. 2 demonstrates a false-positive case. RESULTS: Arthroscopy revealed SLAP lesions in 11/17 patients. Using 3D-MEDIC, SLAP lesions were diagnosed in 14/17 patients by reader 1 and in 13/17 patients by reader 2. Using 2D-PD fs, SLAP lesions were diagnosed in 11/17 patients by reader 1 and 12/17 patients for reader 2. Sensitivity, specificity, PPV, and NPV of 3D-MEDIC were 100.0, 50.0, 78.6, and 100.0% for reader 1; and 100.0, 66.7, 84.6, and 100% for reader 2, respectively. Sensitivity, specificity, PPV, and NPV of 2D-PD fs were 90.9, 83.3, 90.9, and 83.3% for reader 1 and 100.0, 83.3, 91.7, and 100.0% for reader 2. The combination of 2D-PD fs and 3D-MEDIC increased specificity from 50.0 to 83.3% for reader 1 and from 66.7 to 100.0% for reader 2. Interreader agreement was almost perfect with a Cohen's kappa of 0.82 for 3D-MEDIC and 0.87 for PD fs. CONCLUSIONS: With its high sensitivity and NPV, 3D-MEDIC is a valuable tool for the evaluation of SLAP lesions. As the combination with routine 2D-PD fs further increases specificity, we recommend incorporation of 3D-MEDIC as an additional sequence in conventional shoulder protocols in patients with non-specific shoulder pain.

In vivo blood metal ion levels in patients after total shoulder arthroplasty.

BACKGROUND: Products from metal wear have been identified as a potential cause of adverse local tissue reactions and implant failure in total hip arthroplasty. However, the role of metal ion exposure in patients after total shoulder replacement is unclear. The objective of the present study was to determine in vivo blood metal ion levels of cobalt, chromium, and titanium in patients after anatomic total shoulder arthroplasty (TSA) or reverse TSA. METHODS: A consecutive series of patients after anatomic TSA or reverse TSA was evaluated retrospectively. After exclusion of patients with additional metal implants, 40 patients with unilateral anatomic TSA (n = 20) or reverse TSA (n = 20) were available for whole-blood metal ion analysis at a mean follow-up of 28 ± 9.6 months. Twenty-three healthy individuals without metal implants served as a control group. RESULTS: Mean cobalt ion concentrations were 0.18 µg/L (range, 0.1-0.66 µg/L), 0.15 µg/L (range, 0.03-0.48 µg/L), and 0.11 µg/L (range, 0.03-0.19 µg/L), mean chromium ion levels were 0.48 µg/L (range, 0.17-2.41 µg/L), 0.31 µg/L (range, 0.09-1.26 µg/L), and 0.14 µg/L (range, 0.04-0.99 µg/L), and mean titanium ion concentrations were 1.31 µg/L (range, 0.75-4.52 µg/L), 0.84 µg/L (range, 0.1-1.64 µg/L), and 0.62 µg/L (range, 0.32-2.14 µg/L) in the reverse TSA group, the anatomic TSA group, and the control group, respectively. CONCLUSIONS: TSA resulted in elevated metal ion levels compared with healthy controls, although overall metal ion concentrations measured in this study were relatively low. The role of local metal ion exposure in patients with total shoulder replacements should be further investigated.

Impact of spine alignment on the rotator cuff in long-term wheelchair users.

BACKGROUND: We investigated the impact of poor seated posture on the prevalence of rotator cuff tears (RCTs) among wheelchair-dependent individuals with long-standing paraplegia. METHODS: The study included 319 patients. Lateral radiographs of the spine were collected from a database and analyzed to assess the global spinopelvic alignment (SPA). Magnetic resonance images of both shoulders were obtained to detect the presence of cuff tears. Patients were divided into 2 groups: Group RCT-I included all patients with cuff tears (right, left, or bilateral), whereas group RCT-II consisted exclusively of patients with bilateral cuff tears. We used the classification systems developed by Kendall et al and Roussouly et al to assess the sagittal spine alignment and SPA, respectively. Univariate and multivariate analyses were performed. To fit both models (groups RCT-I and RCT-II) to the data, the 4 spine curves according to Roussouly et al were subdivided into 2 groups: Group SPA-I included both type 1 and type 2, whereas group SPA-II included both type 3 and type 4. RESULTS: Magnetic resonance images showed a cuff tear in 192 patients (60.19%) (group RCT-I). Among those, 37 patients (11.60%) had tears in both shoulders (group RCT-II). In group RCT-I, 70.31% of the patients had a kyphotic-lordotic posture. The kyphotic-lordotic posture, a longer duration, and a more rostral neurologic level of injury were highly associated with cuff tear prevalence. In group RCT-II, the multivariate analysis showed that only the duration of spinal cord injury was significantly associated with RCTs. CONCLUSION: Thoracic hyperkyphosis was associated with a markedly high rate of RCTs. The data from this study may provide support for developing preventive strategies.

The subchondral bone layer and glenoid implant design are relevant for primary stability in glenoid arthroplasty.

BACKGROUND: Clinical studies suggest that reaming of the subchondral bone layer to achieve good implant seating is a risk factor for glenoid loosening. This study aims to evaluate (1) the importance of the subchondral bone layer and (2) the influence of the design of the glenoid component. METHODS: Different techniques for preparation of an A1 glenoid were compared: (1) preserving the subchondral bone layer; (2) removal of the subchondral bone layer; (3) implantation of a glenoid component that does not adapt to the native anatomy. Artificial glenoid bones (n = 5 each) were used with a highly standardized preparation and implantation protocol. Biomechanical testing was performed during simulated physiological shoulder motion. Using a high-resolution optical system, the micromotions between implant and bone were measured up to 10,000 motion cycles. RESULTS: At the 10,000 cycle measuring point, significantly more micromotions were found in the subchondral layer removed group than in the subchondral layer preserved group (p = 0.0427). The number of micromotions in the nonadapted group was significantly higher than in the subchondral layer preserved group (p = 0.0003) or the subchondral layer removed group (p = 0.0207). CONCLUSION: Conservative reaming proved important to diminish the micromotions of the glenoid component. Implantation of a glenoid component that matches with the bony underlying glenoid can help to preserve the subchondral bone layer without sacrificing proper implant seating.

Replacement options for the B2 glenoid in osteoarthritis of the shoulder: a biomechanical study.

BACKGROUND: Glenoid replacement in cases of severe glenoid retroversion (RV) or eccentric wear is challenging. The aim of this study was to evaluate different treatment methods under standardized conditions to assist surgeons in the decision-making process. METHODS: Three treatment options for severe glenoid RV (15°) were compared: (1) no RV correction; (2) complete RV correction; (3) no RV correction and implantation of a posterior augmented glenoid (PAG). A highly standardized implantation protocol using artificial glenoid bones (five per group) was chosen, and a physiologic shoulder movement was applied in a biomechanical setting. Micromotions (MM) between glenoid components and bone were quantified using an optical 3D measuring system. RESULTS: In the uncorrected retroversion group, three instances of subluxation of the prosthetic head occurred between 2000 and 4000 cycles. At 2000 cycles, significantly more MM were observed in the uncorrected RV group than in the corrected RV group (p < 0.0001) or to the augmented group (p < 0.0001). At 10|000 cycles, more MM were observed in the posterior augmented group than in the corrected RV group (p < 0.0001). CONCLUSION: If sufficient bone stock is available, retroversion correction should be favored. Posterior augmented glenoids seem to be a suitable treatment option if complete correction of the retroversion is not possible without compromising the glenoid vault. Without correction of the retroversion, high failure rates were observed.

Functional midterm follow-up comparison of stemless total shoulder prostheses versus conventional stemmed anatomic shoulder prostheses using a 3D-motion-analysis.

BACKGROUND: The aim of this study is to compare the functional midterm outcome of stemless shoulder prostheses with standard anatomical stemmed shoulder prostheses and to show that the STEMLESS results are comparable to the STEMMED with respect to active maximum range of shoulder motion (ROM) and Constant score (CS). METHODS: Seventeen patients underwent total shoulder arthroplasty (TSA) in 25 shoulder joints. Stemless TSA was performed in 12 shoulder joints (group STEMLESS), third-generation stemmed TSA in 13 shoulder joints (group STEMMED). Functional results were documented using the CS. 3D-motion-analysis using the Heidelberg upper extremity model (HUX) was conducted to measure active maximum (ROM). RESULTS: The group STEMLESS achieved a CS of 67.9 (SD 12.0) points and the group STEMMED of 70.2 (SD 5.8 points) without significant difference between the groups (p = 0.925). The maximum ROM of the group STEMLESS, ascertained by 3-D-motion-analysis, was in forward flexion 125.5° (SD 17.2°), in extension 49.4° (SD 13.8°), in abduction 126.2° (SD 28.5°) and in external rotation 40.3° (SD 13.9°). The maximum ROM of the group STEMMED, also ascertained by 3-D-motion analysis, was in forward flexion 135.0° (SD 16.8°), in extension 47.2° (SD 11.5°), in abduction 136.3° (SD 24.2°) and in external rotation 40.1° (SD 12.2°). The maximum ROM of the STEMLESS group was lower in forward flexion and abduction, higher in extension and almost identical in external rotation. But there was no significant difference (forward flexion p = 0.174, extension p = 0.470, abduction p = 0.345, external rotation p = 0.978). CONCLUSION: Both types of shoulder prostheses achieve a similar and good active ROM and similar results in CS. TRIAL REGISTRATION: DRKS00013166 , retrospectively registered, 11.10.2017.

Total shoulder arthroplasty: risk factors for intraoperative and postoperative complications in patients with primary arthritis.

BACKGROUND: This study evaluated and identified risk factors for the development of intraoperative and postoperative surgical complications in total shoulder arthroplasty in patients with primary osteoarthritis. METHODS: We evaluated patient-specific factors, including age, sex, body mass index, prior nonarthroplasty surgery, smoking, alcohol consumption, and the American Society of Anesthesiologists (ASA) Physical Status Classification System in 275 patients (76 men, 199 women) with an average age of 68 years (range, 51-85 years). We categorized the number and severity of all complications and correlated these results with the patient-specific factors RESULTS: Twenty-seven complications (9.8%) in 275 shoulder arthroplasties were recorded. We identified 22 patients (8%) with category I complications and 5 (2.8%) with category II complications. Patients with an ASA score of 3 showed an increased likelihood of having a surgical complication compared with the control group with ASA scores of 1 and 2 (odds ratio, 4.28; 95% confidence interval, 1.79-10.20; P < .01). Smokers were more prone to surgical complications than nonsmokers (odds ratio, 5.08; 95% confidence interval, 1.96-13.11; P = .02). CONCLUSION: Surgical complication rates after anatomic total shoulder arthroplasty in patients with primary osteoarthritis correlate with the patient's overall health status and nicotine consumption. This may be useful for predicting the likelihood of surgical complications and may thus prove important for clinicians to better assess and explain possible risks before surgery.

Rare implant-specific complications of the MoPyC radial head prosthesis.

BACKGROUND: According to currently available data, the clinical short-term results of the MoPyC radial head prosthesis (Bioprofile, Tornier, Montbonnot-Saint-Martin, France) seem favorable. However, we have encountered several implant-specific complications in recent years. Hence, this case series reports rare complications after radial head arthroplasty with the MoPyC prosthesis to make surgeons aware of their existence and to provide information about the underlying cause and possible salvage strategies. METHODS: A retrospective chart review from 2011 to 2016 was conducted to identify all adult patients with a minimum 2-year follow-up who underwent or were referred after radial head arthroplasty with the MoPyC radial head prosthesis and experienced implant-related complications. RESULTS: Five patients with 7 implant-related complications were found. One patient experienced breakage of the pyrocarbon head. In another patient, breakage of the stem and-after revision surgery-partial breakage were observed. Disassembly of the prosthesis was seen in 1 case. Extensive periprosthetic stress shielding was seen in 3 patients resulting in symptomatic loosening (1), periprosthetic radial neck fracture (1), and stem migration (1). CONCLUSIONS: Whereas clinical short-term results of the MoPyC radial head prosthesis are satisfactory, rare implant-related complications can occur. Surgeons should be aware of these complications as they may lead to a poor outcome.

Surface and form alterations in retrieved shoulder hemiarthroplasty.

BACKGROUND: Shoulder hemiarthroplasty is a viable treatment for shoulder arthritis, particularly if the natural glenoid is still intact. One of the most common reasons for revision surgery is glenoid erosion, where the cartilage or bone is worn. The aim of the current study was to analyze whether the metallic articular surface of retrieved shoulder hemiarthroplasty is different from new implants. We hypothesized that the surface roughness would increase as a result of the articulation and that metallic wear would be detectable on the implants. METHODS: Included were 13 retrieved and 3 new shoulder hemiarthroplasties. The surface roughness was measured on different sites of the surface (dome of the head and the rim). The implants were further measured using a coordinate measuring machine to gain information on volumetric wear and geometric alterations. The surface was analyzed with a scanning electron microscope to see marks of wear. RESULTS: Compared with new implants, the surface roughness on the retrievals was significantly increased. The roughness parameters within the retrieval group were generally higher at the dome of the head than at the rim; however, this difference was not significant. Apart from shape deviations caused by deformation of the retrievals, no volumetric wear was detectable on the heads. CONCLUSIONS: The current results indicate that the roughness of the surface of the implant and the shape changes occur in vivo and that the material incurs damaged caused by the articulation against the softer cartilage or bone. Increasing roughness of the humeral component may be one cause for glenoid erosion over time.

Reverse arthroplasty for patients with chronic locked dislocation of the shoulder (type 2 fracture sequela).

BACKGROUND: The aim of this multicenter study was to analyze the clinical and radiographic outcome and to report on the types of complications in patients with chronic locked shoulder dislocation treated with reverse shoulder arthroplasty. METHODS: Twenty-two patients with a mean age of 71 years were included. The mean duration of follow-up was 3.5 years. Preoperatively, computed tomography or magnetic resonance imaging scans were performed and analyzed for bone defects and the status of the rotator cuff. Radiographs in 2 planes were obtained before arthroplasty and at final follow-up (mean, 3.5 years; range, 2-9 years). The Constant-Murley score was documented, together with active shoulder flexion, external rotation, and internal rotation. RESULTS: There was a significant increase in mean Constant-Murley score from 13.6 points preoperatively to 47.4 points postoperatively (P < .001). Mean shoulder flexion was 37.7° before arthroplasty and 103° thereafter (P < .001). External rotation increased from -0.5° to 14.7° (P < .003). There were 7 complications (32%), leading to revision surgery in 6 cases (27%). The most common reason for revision surgery was failure of the glenoid component due to bone defects on the glenoid side. Eight patients rated their subjective result as very good, 5 as good, 5 as satisfactory, and 4 as unsatisfactory. CONCLUSION: Reverse shoulder arthroplasty may be a viable treatment option for chronic locked shoulder dislocations with concomitant rotator cuff lesions and an intact glenoid. However, improvement in function is only fair and in this series, there was a high percentage of complications requiring re-operation.

Dynamic contrast-enhanced ultrasound and elastography assess deltoid muscle integrity after reverse shoulder arthroplasty.

BACKGROUND: The outcome after reverse shoulder arthroplasty (RSA) depends on the condition of the deltoid muscle, which we assessed with new ultrasound modalities and electromyography (EMG). Contrast-enhanced ultrasound (CEUS) and acoustic radiation force impulse (ARFI) were applied to assess perfusion and elasticity of the deltoid muscle compared with the clinical and functional outcome. METHODS: The study recruited 64 patients (mean age, 72.9 years) treated with RSA between 2004 and 2013. The deltoid muscle was examined with EMG and ultrasound imaging. Functional scores such as Constant score and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score were assessed. Among other CEUS parameters, the wash-in perfusion index, time to peak, and rise time were compared between the operated-on and contralateral shoulders as well as between patients with above-average and below-average outcome. The stiffness of the deltoid muscle was analyzed with ARFI. RESULTS: After RSA, deltoid perfusion (wash-in perfusion index, Δ = -12% ± 22%, P = .0001) and shoulder function (Constant score, Δ = -14 ± 24, P < .0001) were both inferior compared with the contralateral side. This perfusion deficit was associated with a limited range of motion (time to peak and anteversion: r = -0.290, P = .022). Deltoid perfusion was higher in patients with above-average outcome (rise time, Δ = 33% ± 13%, P = .038). The operated-on deltoid muscles showed higher stiffness than the contralateral muscles (ARFI, Δ = 0.2 ± 0.9 m/s, P = .0545). EMG excluded functionally relevant axillary nerve injuries in the study population. CONCLUSIONS: CEUS revealed reduced mean perfusion of the deltoid muscle after RSA. Reduced perfusion was associated with limited range of motion and below-average outcome. Functional shoulder impairment after RSA might be predicted by noninvasive CEUS as a surrogate parameter for the integrity of the deltoid muscle.

Predictors of medium-term clinical outcomes after total shoulder arthroplasty.

PURPOSE: The study aims to measure the relationship of potential clinical and radiographic predictors and medium-term clinical outcomes after total shoulder arthroplasty in primary osteoarthritis. MATERIALS AND METHODS: In a prospective follow-up study, preoperatively collected clinical and radiographic variables were recorded in 103 patients with an average age of 66 years (range 37-83 years) to measure their influence on the clinical outcome by use of the Constant score. The average length of follow-up was 6 years (range 3-12 years). Radiographs and a computed tomography (CT) of the shoulders were obtained preoperatively for evaluating the acromiohumeral distance, the lateral glenohumeral offset and the morphology of the glenoid, which was classified according to the method by Walch (type-A1 to type-C glenoids). RESULTS: The mean Constant score improved from its preoperative value of 25 points (range 6-54 points) to 65 points (range 10-86 points) postoperatively (p < 0.001). The mean age- and sex-normalized Constant score was similarly improved from 34 points (range 8-78 points) preoperatively to 90 points (range 14-130 points) at the time of follow-up (p < 0.001). The Walch classification of glenoid wear had a significant negative effect (r = -0.32, p < 0.001). The other predictors showed no significant influence on the Constant score (p > 0.05). CONCLUSION: A higher Walch classification is a negative predictor for the postoperative clinical function. The proven significant negative effect  on outcomes in total shoulder arthroplasty emphasizes the importance of the preoperative evaluation of humeral head subluxation and glenoid erosion, which are associated with less favorable postoperative results. The measured internal patient variables gave no negative predictions on the medium-term clinical outcomes in the study population.

Nerve supply of the subscapularis during anterior shoulder surgery: definition of a potential risk area.

PURPOSE: The purpose of the study was to evaluate the position of the subscapular nerves relative to surgical landmarks during exposure and to analyze the pattern of innervation of the subscapularis to avoid injury during anterior shoulder surgery. METHODS: 20 embalmed human cadaveric shoulder specimens were used in the study. The muscular insertions of the subscapular nerves were marked and their closest branches to the musculotendinous junction and the coracoid process were measured in horizontal and vertical distances. In addition, the innervation pattern of each specimen was documented. RESULTS: 14/20 specimens showed an innervation of the subscapularis with an upper, middle and lower subscapular nerve branch. Even though the nerve branches were in average more than 2 cm medial to the musculotendinous junction, minimal distances of 1.1-1.3 cm were found. The mean vertical distance as measured from the medial base of the coracoid to the nerve innervation point into the muscle was 0.7 cm for the upper nerve branch, 2.2 cm for the middle nerve branch and 4.4 cm for the lower nerve branch. CONCLUSIONS: The subscapularis has a variable nerve supply, which increases the risk of muscle denervation during open shoulder surgery. Dissection or release should be avoided at the anterior aspect of the subscapularis muscle more than 1 cm medial to the musculotendinous junction. In approaches with a horizontal incision of the subscapularis, splitting should be performed at a vertical distance of 3.2-3.6 cm to the coracoid base to avoid iatrogenic subscapular nerve injuries.

Three-dimensional motion analysis for validation of shoulder internal rotation.

BACKGROUND: 10% of the points for the Constant-Murley score (CMS) are allocated for the capacity for internal rotation (IR), measured as unassisted active movement of the dorsum of the hand or the thumb to reach different anatomical landmarks. However, there is little information about the validity of this method and no three-dimensional measurement of the degree of IR that is necessary to reach these landmarks. METHODS: Sixteen volunteers with healthy shoulders were recruited. The degree of IR was defined using the following landmarks as described in the CMS: (1) lateral aspect of thigh, (2) buttock, (3) sacroiliac joint, (4) level of waist, (5) vertebra T12, (6) interscapular. The validity of IR measurement was assessed by simultaneous 3D motion analysis. RESULTS: Using the thumb as pointer, there were significant increases in IR from 39.3° at position 1 to 80.4° at position 2, followed by 105.1°, 108.6°, 110.1°, and 125.3° at position 3-6. Taking the dorsum of the hand as pointer, there were significant increases in IR between all positions, starting from 71.2° (position 1) and followed by 99.3°, 104.1°, 110.3°, 115.2°, and 119.7° at positions 2 to 6. Comparing the two measurement methods, a significant difference was found for the amount of IR between positions 1 and 2. CONCLUSION: Measurement of IR as described in the CMS is a suitable method. However, there was an increase of only 10° in IR between positions 3 and 5, which may be hard to measure with a standard goniometer in clinical practice.

Functional results of hemi- and total shoulder arthroplasty according to diagnosis and patient age at surgery.

Background and purpose - There is a lack of information on any associations between the functional outcome and age and diagnosis in patients who have undergone shoulder arthroplasty. We therefore evaluated the functional outcome in "young" and "old" patients treated with either hemiarthroplasty (HA) or total shoulder arthroplasty (TSA) with diverse diagnoses. Patients and methods - The functional results of 496 primary shoulder arthroplasties were analyzed using the Constant score (age- and sex-adjusted) and subjective satisfaction. Patients ≤55 years of age at surgery were defined as "young. Diagnoses were primary osteoarthritis (n = 339), posttraumatic osteoarthritis (n = 78), cuff tear arthropathy (n = 36), avascular necrosis (n = 30), and rheumatoid arthritis (n = 13). Mean length of follow-up was 4 (2-14) years. Results - 70% of the TSA patients were very satisfied with the postoperative result, as compared to 39% after HA. The Constant score and patient satisfaction were similar in the "young" and "old" groups. Pain relief was better in the "old" group. The mean improvement in the Constant score after cuff tear arthropathy (22 points) was inferior to that for primary osteoarthritis (36 points), avascular necrosis (34 points), and rheumatoid arthritis (37 points). Inferior mean Constant scores were also seen for posttraumatic osteoarthritis (29 points) compared to primary osteoarthritis (36 points). 63% of patients with primary osteoarthritis were very satisfied, as compared to only 36% of the patients with posttraumatic osteoarthritis. Interpretation - Shoulder arthroplasty is successful in the medium term for different glenohumeral diseases, irrespective of patient age at surgery. However, the appropriate treatment method for cuff tear and posttraumatic conditions of the shoulder remains to be found, particularly in young patients.

Shoulder joint replacement can improve quality of life and outcome in patients with dysmelia: a case series.

BACKGROUND: Arthroplasty is a proven treatment option for glenohumeral osteoarthritis. Common indications include primary or posttraumatic osteoarthritis, avascular necrosis of the humeral head, rotator cuff tear arthropathy and rheumatoid osteoarthritis. Arthroplasty is rarely performed among patients with glenohumeral dysmelia. An overuse of the upper limb in patients with thalidomide-induced phocomelia and people with similar congenital deformities like dysmelia results in premature wear of the shoulder joint. This study aims to evaluate our experience with cases of glenohumeral osteoarthritis caused by dysmelia and treated with arthroplasty. To date, few reports on the outcome of shoulder arthroplasty exist on this particular patient group. CASE PRESENTATION: We included four dysmelic patients (five shoulders) with substantial glenoid dysplasia in a prospective database after approval by the local ethics committee. Once conservative treatment options had been exhausted, the patients were treated with shoulder arthroplasty and assessed clinically and radiographically before and after surgery. The mean patient age at the time of surgery was 50.4 years. The minimum follow-up time was 24 months (24-91 months). All patients experienced a considerable improvement of range of motion (ROM) and a relief of pain. No intra- or postoperative complications appeared. CONCLUSION: Patients with dysmelia have acceptable short and mid-term results with resurfacing hemiarthroplasty. It is an effective although somewhat complicated method to relieve pain and improve movement. Long-term performance of arthroplasty in patients with dysmelia remains to be seen, particularly with regard to the remaining problem of the altered and often deficient glenoid.

Activity levels after reverse shoulder arthroplasty.

BACKGROUND: Aim of this study was to analyze whether patients undergoing reverse shoulder arthroplasty (RSA) surgery are able to successfully return to sports and afterwards. METHODS: Thirty-eight patients treated with RSA for Cuff Tear Arthropathy (CTA) were included. Two sub-groups were built: Patients who have participated in sports activities within the last 5 years prior surgery [Group A: n = 21 (55 %)] and patients who have never participated in sports [Group B: n = 17 (45 %)]. Evaluation was based on a questionnaire asking types of sports, frequency, and time to return to sports. RESULTS: Mean age in Group A at the time of surgery was 76.2 (65-85) years and 78.4 (68-92) years in Group B. Most patients were women [n = 35 (92 %)]. Mean follow-up was 4.8 years (2.4-9.4) years. Fifteen (71 %) patients in Group A participated in sports at the time prior to surgery. Fourteen (67 %) patients returned to sports after surgery. The returning rate was 93 %. Six (29 %) patients of Group A stated that one reason they underwent shoulder replacement surgery was to continue to participate in sports. All active patients performed swimming at final follow up. CONCLUSIONS: Most patients being active prior to reverse shoulder arthroplasty surgery are successfully able to return to their activity afterwards.