The role of sonication in the diagnosis of periprosthetic joint infection in total shoulder arthroplasty.

An increased sensitivity of sonication compared to periprosthetic tissue cultures in the diagnosis of periprosthetic joint infection (PJI) of hip and knee arthroplasty has been reported. The goal of this study was to determine if there is also an added value of implant sonication in the diagnosis of PJI in total shoulder arthroplasty (TSA). A retrospective analysis of patients who underwent removal of their TSA combined with sonication of the implant for suspicion of PJI between April 2009 and August 2017 was performed. The diagnosis of PJI was based on the major criteria described by Parvizi. We calculated sensitivity, specificity, predictive values, likelihood ratios and diagnostic accuracy for sonication cultures in comparison with periprosthetic tissue cultures. Data from 41 patients were analysed. Standard synovial fluid cultures combined with intraoperative periprosthetic tissue cultures had a sensitivity of 95%, specificity of 95% and total accuracy of 95%. Sonication cultures had a sensitivity of 91%, specificity of 68% and total accuracy of 80%. Six patients had negative standard cultures but positive sonication cultures. In patients with only one positive standard culture, the pathogen of the sonication culture corresponded to the pathogen of the positive soft tissue culture. We found a possible added value of sonication of TSA in the diagnosis of PJI in conjunction with standard intraoperative cultures. In some patients with suspicion of low-grade TSA infection, sonication could identify a possible causal microorganism despite negative standard cultures.

Determination of predisposing scapular anatomy with a statistical shape model-Part II: shoulder osteoarthritis.

HYPOTHESIS AND BACKGROUND: Shoulder osteoarthritis can be divided into different glenoid types (A, B, C, and D) and subtypes. The aim of this study was to investigate if there is an association between the prearthropathy scapular anatomy, shoulder osteoarthritis, and different glenoid types and subtypes. METHODS: Using principal components analysis, a statistical shape model (SSM) of the scapula was constructed from a data set of 110 computed tomographic (CT) scans. These subjects formed the control group. Next, CT scan images of 117 patients with osteoarthritis were classified according to the modified Walch classification. A complete 3-dimensional (3D) scapular bone model was created for every patient, and using the SSM, a reconstruction of their prearthropathy scapular anatomy was performed. Automated 3D measurements were performed in both the patient and control group to obtain glenoid version and inclination, critical shoulder angle (CSA), posterior acromial slope (PAS), lateral acromion angle, scapular offset, and the rotational alignment of the coracoacromial complex. These parameters were compared between controls, patients with osteoarthritis, and glenoid types and subtypes. RESULTS: Mean version and inclination for the control group was 6° retroversion and 8° superior inclination (both SD 4°). The mean CSA, PAS, coracoid-posterior acromion angle, posterior acromion-scapular plane angle, and fulcrum axis ratio were 30° (SD 4°), 64° (SD 8°), 116° (SD 9°), 55° (SD 7°), and 46% (SD 4%), respectively. Patients with osteoarthritis had a significant lower CSA, posterior acromion-scapular plane angle, coracoid-posterior acromion angle, and fulcrum axis ratio (27°, 50°, 111°, and 44%, all P < .001). We found a significant difference between the control group and the respective glenoid types for the following parameters: mean CSA and coracoid-posterior acromion angle for A glenoids (27°, P = .001, and 111°, P = .007); mean version, CSA, PAS, coracoid-posterior acromion angle, posterior acromion-scapular plane angle, and fulcrum axis ratio for B glenoids (11°, 27°, 71°, 111°, 49°, and 43%, all P < .001); and mean version, CSA, and posterior acromion-scapular plane angle for D glenoids (2°, P = .002, 26°, P = .003, and 48°, P = .007). DISCUSSION: There seems to be an association between prearthropathy scapular anatomy and shoulder osteoarthritis. A small lateral extension and less posterior rotation of the acromion is associated with shoulder osteoarthritis and is present in almost all types and subtypes of glenoid morphology. Furthermore, B and D glenoids are associated with, respectively, a more and less pronounced prearthropathy glenoid retroversion.

Determination of pre-arthropathy scapular anatomy with a statistical shape model: part I-rotator cuff tear arthropathy.

HYPOTHESIS AND BACKGROUND: Rotator cuff tear arthropathy (RCTA) is a pathology characterized by a massive rotator cuff tear combined with acromiohumeral and/or glenohumeral arthritis. The severity of RCTA can be staged according to the Hamada classification. Why RCTA develops in some patients is unknown. Furthermore, in RCTA patients, distinctly different articular damage patterns can develop on the glenoid side as categorized by the Sirveaux classification (glenoid erosion). The goal of this study was to determine whether an association exists between scapular anatomy and RCTA and different severity stages of RCTA, as well as the associated glenoid erosion types. METHODS: A statistical shape model of the scapula was constructed from a data set of 110 computed tomography scans using principal component analysis. Sixty-six patients with degenerative rotator cuff pathology formed the control group. The computed tomography scan images of 89 patients with RCTA were included and grouped according to the Hamada and Sirveaux classifications. A complete 3-dimensional scapular bone model was created, and statistical shape model reconstruction was performed. Next, automated 3-dimensional measurements of glenoid version and inclination, scapular offset, the critical shoulder angle (CSA), the posterior acromial slope (PAS), and the lateral acromial angle (LAA) were performed. All measurements were then compared between controls and RCTA patients. RESULTS: The control group had a median of 7° of retroversion (variance, 16°), 8° of superior inclination (variance, 19°), and 106 mm of scapular offset (variance, 58 mm). The median CSA, PAS, and LAA were 30° (variance, 14°), 65° (variance, 60°), and 90° (variance, 17°), respectively. In terms of inclination, version, scapular offset, and the PAS, we found no statistically significant differences between the RCTA and control groups. For RCTA patients, the median CSA and median LAA were 32° (P ≤ .01) and 86° (P ≤ .01), respectively. For all investigated parameters, we did not find any significant difference between the different stages of RCTA. Patients with type E3 erosion had a different pre-arthropathy anatomy with increased retroversion (12°, P = .006), an increased CSA (40°, P ≤ .001), and a reduced LAA (79°, P ≤ .001). DISCUSSION: Our results seem to indicate that a 4° more inferiorly tilted and 2° more laterally extended acromion is associated with RCTA. RCTA patients in whom type E3 erosion develops have a distinct pre-arthropathy scapular anatomy with a more laterally extended and more inferiorly tilted acromion and a more retroverted glenoid in comparison with RCTA patients with no erosion. The pre-arthropathy scapular anatomy does not seem to differ between patients with different stages of RCTA.

Management of periprosthetic infection after reverse shoulder arthroplasty.

BACKGROUND: Periprosthetic shoulder infection (PSI) remains a devastating complication after reverse shoulder arthroplasty (RSA). Currently, scientific data related to the management of PSI are limited, and the optimal strategy and related clinical outcomes remain unclear. Guidelines from the Infectious Diseases Society of America for the management of periprosthetic joint infection are mainly based on data from patients after hip and knee arthroplasty. The aim of this study was to evaluate whether these guidelines are also valid for patients with PSI after RSA. In addition, the functional outcome according to the surgical intervention was assessed. METHODS: An RSA database was retrospectively reviewed to identify infections after primary and revision RSAs, diagnosed between 2004 and 2018. Data collected included age, sex, indication for RSA, causative pathogen, surgical and antimicrobial treatment, functional outcome, and recurrence. RESULTS: Thirty-six patients with a PSI were identified. Surgical treatment was subdivided into débridement and implant retention (DAIR) (n = 6, 17%); 1-stage revision (n = 1, 3%); 2-stage revision (n = 16, 44%); multiple-stage revision (>2 stages) (n = 7, 19%); definitive spacer implantation (n = 2, 6%); and resection arthroplasty (n = 4, 11%). The most common causative pathogens were Staphylococcus epidermidis (n = 11, 31%) and Cutibacterium acnes (n = 9, 25%). Recurrence was diagnosed in 4 patients (11%), all of whom were initially treated with a DAIR approach. The median follow-up period was 36 months (range, 24-132 months). CONCLUSION: PSI is typically caused by low-virulence pathogens, which often are diagnosed with a delay, resulting in chronic infection at the time of surgery. Our results indicate that treatment of patients with chronic PSI with DAIR has a high recurrence rate. In addition, implant exchange (ie, 1- and 2-stage exchange) does not compromise the functional result as compared with implant retention. Thus, patients with chronic PSI should be treated with implant exchange. Future research should further clarify which surgical strategy (ie, 1-stage vs. 2-stage exchange) has a better outcome overall.

Automated muscle elongation measurement during reverse shoulder arthroplasty planning.

BACKGROUND: Adequate deltoid and rotator cuff elongation in reverse shoulder arthroplasty is crucial to maximize postoperative functional outcomes and to avoid complications. Measurements of deltoid and rotator cuff elongation during preoperative planning can support surgeons in selecting a suitable implant design and position. Therefore, this study presented and evaluated a fully automated method for measuring deltoid and rotator cuff elongation. METHODS: Complete scapular and humeral models were extracted from computed tomography scans of 40 subjects. First, a statistical shape model of the complete humerus was created and evaluated to identify the muscle attachment points. Next, a muscle wrapping algorithm was developed to identify the muscle paths and to compute muscle lengths and elongations after reverse shoulder arthroplasty implantation. The accuracy of the muscle attachment points and the muscle elongation measurements was evaluated for the 40 subjects by use of both complete and artificially created partial humeral models. Additionally, the muscle elongation measurements were evaluated for a set of 50 arthritic shoulder joints. Finally, a sensitivity analysis was performed to evaluate the impact of implant positioning on deltoid and rotator cuff elongation. RESULTS: For the complete humeral models, all muscle attachment points were identified with a median error < 3.5 mm. For the partial humeral models, the errors on the deltoid attachment point largely increased. Furthermore, all muscle elongation measurements showed an error < 1 mm for 75% of the subjects for both the complete and partial humeral models. For the arthritic shoulder joints, the errors on the muscle elongation measurements were <2 mm for 75% of the subjects. Finally, the sensitivity analysis showed that muscle elongations were affected by implant positioning. DISCUSSION: This study presents an automated method for accurately measuring muscle elongations during preoperative planning of shoulder arthroplasty. The results show that the accuracy in measuring muscle elongations is higher than the accuracy in indicating the muscle attachment points. Hence, muscle elongation measurements are insensitive to the observed errors on the muscle attachment points. Related to this finding, muscle elongations can be accurately measured for both a complete humeral model and a partial humeral model. Because the presented method also showed accurate results for arthritic shoulder joints, it can be used during preoperative shoulder arthroplasty planning, in which typically only the proximal humerus is present in the scan and in which bone arthropathy can be present. As the muscle elongations are sensitive to implant positioning, surgeons can use the muscle elongation measurements to refine their surgical plan.

The effectiveness of Botulinum Toxin A for treatment of upper limb impairments and dysfunctions in breast cancer survivors: A randomised controlled trial.

OBJECTIVE: To examine the effectiveness of a single Botulinum Toxin A (BTX-A) infiltration in the pectoralis major muscle, in addition to a standard physical therapy (PT) programme on upper limb impairments and dysfunctions after breast cancer treatment. METHODS: Fifty breast cancer patients with persistent pain 3 months after finishing treatment participated in a double-blinded randomised controlled trial. The intervention group received a single BTX-A infiltration. The control group received a placebo (saline) infiltration. Within one week after the infiltration, all patients attended an individual PT programme (12 sessions) during the first 3 months. Outcome parameters were active shoulder range of motion, upper limb strength, scapular statics and shoulder function. Measures were taken before the intervention, at 1, 3 (i.e. after the intervention) and 6 months follow-up. RESULTS: No differences between groups were found for all outcome parameters over the course of 6 months. However, overall beneficial effects of the PT for active forward flexion shoulder range of motion and shoulder function were found in both groups. CONCLUSION: A single Botulinum Toxin A (BTX-A) infiltration in the pectoralis major muscle, in addition to a PT programme cannot be recommended to treat upper limb impairments and dysfunctions after breast cancer treatment.

How much bone support does an anatomic glenoid component need?

BACKGROUND: An important reason for failure of anatomic total shoulder arthroplasty is glenoid component loosening. We investigated the effect of backside bone support on the risk of failure of a glenoid component. METHODS: A finite element model was developed. Virtual surgery was performed for 2 types of glenoid components (cemented all polyethylene [PE] vs. metal backed [MB]), both with gradually decreasing backside bone support. Both bone failure and fixation failure were analyzed. The percentages of bone failure and fixation failure in terms of the critical cement volume (CCV) and micromotion-threshold percentage ratio (MTPR) for the PE and MB components, respectively, were defined and compared. RESULTS: For the reference PE model, the percentages of bone failure and fixation failure (CCV) were 17% and 34%, respectively. With eccentric loading for the MB component, the percentages of bone failure and fixation failure (MTPR) were 6% and 3%, respectively. A global increase in failure was observed with decreasing bone support. The increase in fixation failure, starting from the reference values (MTPR vs. CCV), was relatively more pronounced for the MB component (136% vs. 128%). DISCUSSION: Decreasing backside bone support for an anatomic glenoid component leads to an increased risk of fixation and bone failure. For PE components, decreasing backside support to 95% bone support had only a limited effect. In the case of an MB component, we noticed an increase in micromotion and bone failure already starting from 97% bone support. We conclude that an anatomic glenoid component should always be implanted while maximizing backside bone support.

Automated quantification of glenoid bone defects using 3-dimensional measurements.

BACKGROUND: Assessment of glenoid bone defects is important to select the optimal glenoid component design during shoulder arthroplasty planning and implantation. This study presents a fully automated method to describe glenoid bone loss using 3-dimensional measurements without the need for a healthy contralateral reference scapula. METHODS: The native shape of the glenoid is reconstructed by fitting a statistical shape model (SSM) of the scapula. The total vault loss percentage, local vault loss percentages, defect depth, defect area percentage, and subluxation distance and region are computed based on a comparison of the reconstructed and eroded glenoids. The method is evaluated by comparing its results with a contralateral bone-based reconstruction approach in a data set of 34 scapula and humerus pairs with unilateral glenoid bone defects. RESULTS: The SSM-based defect measurements deviated from the contralateral bone-based measurements with mean absolute differences of 5.5% in the total vault loss percentage, 4.5% to 8.0% in the local vault loss percentages, 1.9 mm in the defect depth, 14.8% in the defect area percentage, and 1.6 mm in the subluxation distance. The SSM-based method was statistically equivalent to the contralateral bone-based method for all parameters except the defect area percentage. CONCLUSION: The presented method is able to automatically analyze glenoid bone defects using 3-dimensional measurements without the need for a healthy contralateral bone.

Outcomes of reverse total shoulder arthroplasty with postoperative scapular fracture. A systematic review.

Postoperative scapular fractures are infrequent complications of reverse total shoulder arthroplasty (RTSA). The aim of this study is to discuss the functional outcome, clinical outcome and pain scores of these fractures and to analyze these outcome results based on fracture location. A systematic review in accordance with the PRISMA guidelines was conducted. Pubmed, EMBASE, Web of Science, Cochrane library and Ovid have been screened. A total of 78 RTSA in 12 articles were retained for qualitative analysis. The average minimum follow- up was 33.3 ± 14.4 months (range 12-60 months) and the mean age was 74.4 ± 5.6 years (range 63-85 years) with a mean female percentage of 90.9%. Overall, the mean DASH score was 39.8 ± 9.4 points (range 29.5- 48.0 points), ASES score 53.4 ± 23.3 points (range 13.3-95.0 points), SST 3.2 ± 2.2 points (range 0.0- 5.1 points), the only OSS 28.0 points and Constant- Murley shoulder score 50.5 ± 20.0 points (range 31.5- 69.0). The mean anterior elevation was 91.5° ± 30.7° (range 46.0°-160.0°), abduction 87.8° ± 21.8° (range 55.0°-125.0°), external rotation 33.2° ± 22.2° (range 9.0°-85°) and the only internal rotation was 60.0°. The VAS score averaged of 3.8 ± 2.8 points (range 0.8-9.0 points). A subgroup analysis of acromial and scapular spine fractures was performed. Acromial and scapular spine fractures have an undeniable effect on RTSA outcomes, however patients still improve compared to their preoperative state. We advise to consider acromial and scapular fractures as different problems, as prognosis is worse for more medial fractures.

Treatment of severe glenoid deficiencies in reverse shoulder arthroplasty: the Glenius Glenoid Reconstruction System experience.

BACKGROUND: The treatment of glenoid bone deficiencies in primary or revision total shoulder arthroplasty is challenging. This retrospective study evaluated the short-term clinical and radiologic results of a new custom-made patient-specific glenoid implant. METHODS: We treated 10 patients with severe glenoid deficiencies with the Glenius Glenoid Reconstruction System (Materialise NV, Leuven, Belgium). Outcome data included a patient-derived Constant-Murley score, a visual analog score (VAS), a satisfaction score, the 11-item version of the Disabilities of the Arm, Shoulder and Hand score, and the Simple Shoulder Test. We compared the postoperative position of the implant with the preoperative planned position on computed tomography scans. RESULTS: At an average follow-up period of 30.5 months, the mean patient-derived Constant-Murley score was 41.3 ± 17.5 points (range, 18-76 points) with a visual analog scale of 3.3 ± 2.5 points (range, 0-7 points). The mean 11-item version of the Disabilities of the Arm, Shoulder and Hand score was 35.8 ± 18.4 (range, 2-71), and the mean Simple Shoulder Test was 47.5% ± 25.3% (range, 8%-92%). Eight patients reported the result as better (n = 3) or much better (n = 5). One patient had an elongation of the brachial plexus, and 1 patient had a period of instability. The average preoperative glenoid defect size was 9 ± 4 cm3 (range, 1-14 cm3). The mean deviation between the preoperative planned and the postoperative version and inclination was 6° ± 4° (range 1°-16°) and 4° ± 4° (range 0°-11°), respectively. CONCLUSION: Early results of the Glenius Glenoid Reconstruction System are encouraging. Adequate pain relief, a reasonable functionality, and good patient satisfaction can be obtained in these difficult cases. Further follow-up will determine the bony ingrowth and subsequent longevity of this patient-specific glenoid component.

Effectiveness of Botulinum Toxin A for Persistent Upper Limb Pain After Breast Cancer Treatment: A Double-Blinded Randomized Controlled Trial.

OBJECTIVE: To investigate the effect of a single botulinum toxin A (BTX-A) infiltration in the pectoralis major muscle in addition to a standard physical therapy program for treatment of persistent upper limb pain in breast cancer survivors. DESIGN: Double-blinded (patient and assessor) randomized controlled trial. SETTING: A university hospital. PARTICIPANTS: Breast cancer patients (N=50) with pain. INTERVENTION: The intervention group received a single BTX-A infiltration. The control group received a placebo (saline) infiltration. Within 1 week after the infiltration, all patients attended an individual physical therapy program (12 sessions) during the first 3 months and a home exercise program up to 6 months after infiltration. MAIN OUTCOME MEASURES: The primary outcome was change in pain intensity at the upper limb (visual analog scale, 0-100) after 3 months. Secondary outcomes were prevalence rate of pain, pressure hypersensitivity, pain quality, shoulder function, and quality of life. Measures were taken before the intervention and at 1, 3, and 6 months' follow-up. RESULTS: No significant difference in change in pain intensity after 3 months was found (mean difference in change, 3/100; 95% confidence interval [CI], -13 to 19). From baseline up to 6 months, a significantly different change in upper limb pain intensity was found between groups in favor of the intervention group (mean difference in change, 16/100; 95% CI, 1-31). CONCLUSIONS: A single BTX-A infiltration in combination with an individual physical therapy program significantly decreased pain intensity at the upper limb in breast cancer survivors up to 6 months. However, the effect size was not clinically relevant, and no other beneficial effects were found.

Can the contralateral scapula be used as a reliable template to reconstruct the eroded scapula during shoulder arthroplasty?

HYPOTHESIS: The contralateral scapula can be used as a reliable template to determine scapular offset, glenoid inclination, and version of the native scapula in view of reconstructing pathologic scapulae. METHODS: Three-dimensional measurements of scapular offset, inclination, and version were performed using data from a set of 50 bilateral computed tomography scans of full scapulae to determine direct side-to-side differences. RESULTS: The scapula pairs had a mean bilateral difference of 2 mm in offset, 2° in inclination, and 2° in version. Ninety percent of the scapula pairs showed an offset difference smaller than 3 mm. In 96% and 94% of the scapula pairs, the inclination difference and version difference, respectively, were smaller than 5°. The maximum bilateral difference for offset, inclination, and version was 6 mm, 6°, and 8°, respectively. DISCUSSION AND CONCLUSION: The anatomic parameters of scapular offset, glenoid inclination, and version are quite symmetrical and fall into the currently technically feasible accuracy of shoulder arthroplasty implantation. The healthy scapula can be used as a template to guide the reconstruction of the glenoid during shoulder arthroplasty planning in the case of unilateral advanced arthropathy.

Virtual reconstruction of glenoid bone defects using a statistical shape model.

BACKGROUND: Description of the native shape of a glenoid helps surgeons to preoperatively plan the position of a shoulder implant. A statistical shape model (SSM) can be used to virtually reconstruct a glenoid bone defect and to predict the inclination, version, and center position of the native glenoid. An SSM-based reconstruction method has already been developed for acetabular bone reconstruction. The goal of this study was to evaluate the SSM-based method for the reconstruction of glenoid bone defects and the prediction of native anatomic parameters. METHODS: First, an SSM was created on the basis of 66 healthy scapulae. Then, artificial bone defects were created in all scapulae and reconstructed using the SSM-based reconstruction method. For each bone defect, the reconstructed surface was compared with the original surface. Furthermore, the inclination, version, and glenoid center point of the reconstructed surface were compared with the original parameters of each scapula. RESULTS: For small glenoid bone defects, the healthy surface of the glenoid was reconstructed with a root mean square error of 1.2 ± 0.4 mm. Inclination, version, and glenoid center point were predicted with an accuracy of 2.4° ± 2.1°, 2.9° ± 2.2°, and 1.8 ± 0.8 mm, respectively. DISCUSSION AND CONCLUSION: The SSM-based reconstruction method is able to accurately reconstruct the native glenoid surface and to predict the native anatomic parameters. Based on this outcome, statistical shape modeling can be considered a successful technique for use in the preoperative planning of shoulder arthroplasty.

Rotator cuff healing after needling of a calcific deposit using platelet-rich plasma augmentation: a randomized, prospective clinical trial.

BACKGROUND: Arthroscopic needling of a rotator cuff calcification is a highly reliable operation in terms of pain relief and return of function. However, during the needling process, a cuff defect is created. Little is known about the evolution of this defect. METHODS: We conducted a prospective, randomized controlled clinical trial to investigate the evolution of the aforementioned defect and the role of platelet-rich plasma (PRP) augmentation in this healing process. Patients were randomized to either group 1 (PRP, n = 20) or group 2 (no PRP [control group], n = 20). Patients in group 1 received a perioperative PRP infiltration at the rotator cuff defect, whereas the control group did not. Patients were assessed clinically preoperatively and postoperatively at 6 weeks, 3 and 6 months, and 1 year. The Constant score, Simple Shoulder Test, and QuickDASH (short version of Disabilities of the Arm, Shoulder and Hand questionnaire) were used as outcome measures. The evolution of the cuff defect was evaluated on sonography at 3 and 6 months and with magnetic resonance imaging after 1 year. RESULTS: All patients improved significantly after surgery (P < .05). There was no difference in clinical outcome or rotator cuff healing between groups. We observed a high rate of persistent rotator cuff defects after 1 year in both groups. The presence of residual cuff defects did not influence the clinical outcome. CONCLUSION: Arthroscopic needling is an operation with a predictive, good clinical outcome. We found a high rate of persistent rotator cuff defects after 1 year. This study could not identify any beneficial effect of the addition of PRP on rotator cuff healing. LEVEL OF EVIDENCE: Level II; Randomized Controlled Trial; Treatment Study.

A patient-specific guide for optimizing custom-made glenoid implantation in cases of severe glenoid defects: an in vitro study.

BACKGROUND: Glenoid component and screw malpositioning in cases of severe glenoid defects might result in complications. We examined the efficacy of a surgical method to treat severe glenoid defects, including a custom-made glenoid component and accurate screw positioning, using a patient-specific positioning guide. METHODS: Glenoid defects were created in 10 cadaveric shoulders. Computed tomography images were used to plan reversed shoulder arthroplasty and design patient-specific glenoid components. A patient-specific positioning guide was designed for 5 specimens. The remaining 5 specimens were implanted without the guide. Computed tomography images were used to determine the postoperative glenoid component and screw positions. Differences from the preoperatively planned implant and screw positions were calculated. RESULTS: The patient-specific positioning guide significantly reduced the angular deviations from the planned glenoid implant positioning (P < .05) and also significantly improved the positioning of the screws (P < .001). In the group without the guide, the average total intraosseous screw length was 52% of the ideal preoperatively planned length compared with 89% for the group with the guide. A strong correlation (r = -0.85) was found between the orientation of the implant and the postoperative total intraosseous screw length. CONCLUSIONS: A patient-specific positioning guide significantly improves the position and fixation of a custom-made glenoid component in cases of severe glenoid defects.

A nondestructive method to verify the glenosphere-baseplate assembly in reverse shoulder arthroplasty.

BACKGROUND: Glenoid dissociation is a rare postoperative complication in reverse shoulder arthroplasty that has severe consequences for the patient and requires revision in most cases. A mechanically compromised Morse taper is hypothesized to be the main cause of this complication, with bony impingements and soft tissue interpositioning being cited as the most important problems. Intraoperative assessment of the taper assembly is challenging. Current methods require applying considerable torque to the glenosphere or relying on radiographs. MATERIALS AND METHODS: This in vitro study demonstrates how the assembly quality can be accurately determined in a nondestructive way by exploiting the implant-specific relation between screw and Morse taper characteristics by measuring the angular rotation-torque curve. RESULTS: The feasibility of the method is demonstrated on 2 reverse implant models. Several data features that can statistically discriminate between optimal and suboptimal assemblies are proposed. CONCLUSION: Suboptimal assemblies can be detected using the method presented, which could easily be integrated in the current surgical workflow. Clinical recommendations based on the method's rationale are also presented, allowing detection of the most severe defect cases with surgical instruments currently in use.

Joining the fingers: a HOXD13 Story.

Synpolydactyly (SPD, OMIM 186000) is a rare congenital limb disorder characterized by syndactyly between the third and fourth fingers and between the fourth and fifth toes, with partial or complete digit duplication in the syndactylous web. The majority of these anomalies co-segregate with mutations in the HOXD13 gene,a homeobox transcription factor crucial for distal limb development. Different classes of HOXD13 mutations are involved in the pathogenesis of synpolydactyly, but an unequivocal genotype­phenotype correlation cannot always be achieved due to the clinical heterogeneity and reduced penetrance of SPD. All mutations identified so far mapped to the N-terminal polyalanine tract or to the C-terminal homeodomain of HOXD13,causing typical or atypical features of SPD, respectively. However, mutations outside of these domains cause a broad variety of clinical features that complicate the differential diagnosis. The existing animal models that are currently used to study HOXD13 (mal)function are therefore instrumental in unraveling potential genotype-phenotype correlations. Both mouse- and chick-based approaches allow the in vivo study of the pathogenic mechanism by which HOXD13 mutations cause SPD phenotypes as well as help in identifying the transcriptional targets.

An N-terminal G11A mutation in HOXD13 causes synpolydactyly and interferes with Gli3R function during limb pre-patterning.

Synpolydactyly (SPD) is a distal limb anomaly characterized by incomplete digit separation and the presence of supernumerary digits in the syndactylous web. This phenotype has been associated with mutations in the homeodomain or polyalanine tract of the HOXD13 gene. We identified a novel mutation (G11A) in HOXD13 that is located outside the previously known domains and affects the intracellular half life of the protein. Misexpression of HOXD13(G11A) in the developing chick limb phenocopied the human SPD phenotype. Finally, we demonstrated through in vitro studies that this mutation has a destabilizing effect on GLI3R uncovering an unappreciated mechanism by which HOXD13 determines the patterning of the limb.

Frozen shoulder and the Big Five personality traits.

BACKGROUND: In the past, several studies have suggested the existence of a "periarthritic personality" in patients with frozen shoulder. We conducted a study to determine differences in personality traits in patients with primary and secondary frozen shoulders. MATERIALS AND METHODS: We prospectively evaluated 118 patients (84 women and 34 men; mean age, 53.8 years; SD 7.56) with a frozen shoulder. Of these patients, 48 had an idiopathic frozen shoulder and 70 had a secondary frozen shoulder. Personality traits were determined by the NEO Five-Factor Inventory (NEO-FFI) scale. This questionnaire measures the 5 major personality traits and is based on the norms determined in a neutral test situation for 2415 controls. RESULTS: Compared with healthy controls, no differences in personality traits were found in patients with primary and secondary frozen shoulder, except for Conscientiousness and Extraversion, for which patients with secondary frozen shoulder scored significantly higher than healthy controls. Patients with primary frozen shoulder scored significantly higher on Openness to Experience than did patients with secondary frozen shoulder; on the other 4 Big Five personality traits, no significant differences were found between patients with primary and secondary frozen shoulder. More specifically, patients with idiopathic frozen shoulder did not score higher on the trait Neuroticism as would be expected from previous publications. CONCLUSIONS: Our study results do not indicate that patients with an idiopathic frozen shoulder have a specific personality compared with healthy controls. Only a few differences were found in personality traits when the entire frozen shoulder group was compared with healthy controls and between patients with primary and secondary frozen shoulders. The results of this study suggest that these differences are not sufficient to speak about a specific "frozen shoulder personality."

A glenoid reaming study: how accurate are current reaming techniques?

BACKGROUND: Correct reaming of a degenerative glenoid can be a difficult procedure. We investigated how the quality of the reamed surface is influenced by different reamers, by the surgeon's experience, and by glenoid erosion patterns. MATERIAL AND METHODS: Three shoulder surgeons performed reaming procedures with different types of reamers (flat, convex, K-wire guided, and nipple guided) on a series of similarly sized uniconcave and biconcave glenoids. The reproducibility of reaming and the effect of different reamers on different-shaped glenoids were measured and evaluated. RESULTS: The center and direction of reaming were constant for all surgeons in the case of type A glenoids. For type B2 glenoids, the center and direction of reaming differed significantly between surgeons. The congruity of the reamed surface was better after flat reaming than after convex reaming. Whether the reamers were guided by a central K-wire or by a nipple had no significant effect on the reamed surface. The experience of the surgeon had no effect on the congruity of reaming. CONCLUSIONS: Reaming of a uniconcave glenoid is reproducible, but reaming of a biconcave glenoid seems much more difficult. Erosion and deformity of the glenoid influence the accuracy of reaming the most. Surgical experience plays a less important role. We conclude that there is a need for guidance in reaming of biconcave glenoids.