Impact of glenosphere size on clinical outcomes after reverse total shoulder arthroplasty: an analysis of 297 shoulders

BACKGROUND

Although increasing glenosphere diameter has been found to increase passive range of motion (ROM) in simulated models of reverse total shoulder arthroplasty (rTSA), the clinical implications of glenosphere size are unclear. The purpose of our study was to determine the impact that glenosphere size had on short-term and midterm clinical outcomes, specifically American Shoulder and Elbow Surgeons (ASES) scores and ROM.

METHODS

Prospectively collected data comparing patients receiving an rTSA with either a 38- or 42-mm glenosphere after a minimum 2-year follow-up were obtained. Clinical outcome measures included active ROM and ASES scores.

RESULTS

We included 297 primary rTSAs in 290 patients: a 38-mm-diameter glenosphere was used in 160 shoulders and a 42-mm-diameter glenosphere in 137 shoulders. Of the patients, 191 were women and 99 were men. The mean age at the time of surgery was 72 years (range, 50-88 years). At last follow-up, improvements in active forward elevation (aFE) and active external rotation (aER) were significantly greater in shoulders with a 42-mm glenosphere (+59° vs +44° for aFE and +24° vs +18° for aER). Female shoulders treated with a 42-mm glenosphere had significantly greater improvements in aFE, aER, and functional scores. Male shoulders treated with a 38-mm glenosphere had significantly greater improvements in pain levels and ASES scores but less improvement in aFE. Complications and rates of scapular notching were similar between glenosphere sizes.

CONCLUSIONS

Patients treated with 42-mm glenospheres had greater improvements in aFE and aER when compared with 38-mm glenospheres. Our results suggest a potential association among gender, glenosphere size, and improvement in clinical outcome scores.

LEVEL OF EVIDENCE

Level III; Retrospective Cohort Design; Treatment Study.

Lateralized Center of Rotation and Lower Neck-Shaft Angle Are Associated With Lower Rates of Scapular Notching and Heterotopic Ossification and Improved Pain for Reverse Shoulder Arthroplasty at 1 Year

Heterotopic ossification and scapular notching are common following reverse total shoulder arthroplasty. Compared with the original Grammont-style prosthesis with a medialized center of rotation (COR) and a 155° neck-shaft angle, lateralization of COR and reduction of neck-shaft angle have been associated with decreased incidence of scapular notching. The authors hypothesized that these design features may also be effective in reducing heterotopic ossification after reverse total shoulder arthroplasty. Ninety-seven consecutive patients who underwent reverse total shoulder arthroplasty performed by a single surgeon were included in the study. Forty-eight patients received a Grammont-style prosthesis, and 49 received a prosthesis with either 6 mm or 10 mm of lateral COR offset and a 135° neck-shaft angle. Radiographs at 1-year follow-up were reviewed by 2 surgeons for notching and heterotopic ossification. Patient-reported outcome scores and range of motion were also compared between the groups. More patients in the Grammont-style group showed scapular notching (Grammont, 35.4%; lateral COR, 12.2%; P=.018) and heterotopic ossification (Grammont, 47.9%; lateral COR, 22.4%; P=.009). The lateralized COR group reported lower pain on the visual analog scale (Grammont mean, 1.1; lateral COR mean, 0.5; P=.01) and trended toward better American Shoulder and Elbow Surgeons scores (Grammont mean, 77.2; lateral COR mean, 83.4; P=.05). However, range of motion was similar between the 2 groups. Compared with the Grammont-style prosthesis, the lateralized COR prosthesis with a decreased neck-shaft angle resulted in a lower incidence of both scapular notching and heterotopic ossification as well as better pain scores and a trend toward improved function at 1 year after reverse total shoulder arthroplasty. [Orthopedics. 2018; 41(4):230-236.].

Radiographic changes and clinical outcomes associated with an adjustable diaphyseal press-fit humeral stem in primary reverse shoulder arthroplasty

BACKGROUND

Press-fit humeral fixation in reverse shoulder arthroplasty (RSA) has become increasingly popular; however, radiographic analysis of these stems is limited. We aimed to evaluate the radiographic and clinical outcomes of an adjustable diaphyseal press-fit humeral stem in primary RSA.

METHODS

We conducted a retrospective review of 232 primary RSAs in 219 patients performed by a single surgeon using this system. Radiographic outcomes were evaluated in patients with at least 2 years of radiographic follow-up. Standardized postoperative digital radiographs were analyzed for loosening, osteolysis, and stress shielding. Clinical outcomes in patients who also had complete clinical data sets were evaluated at the most recent follow-up.

RESULTS

Radiographic evidence of loosening was identified in 1 RSA (0.4%) associated with deep infection. Aseptic loosening was not observed. No stems were identified as being at high risk for loosening. Internal stress shielding was observed proximal to the coated diaphyseal component in 226 shoulders (97.4%). This finding was often visible at 3 months (92.7%) and predictably progressed on subsequent radiographs. Progression beyond the 2-year period was rarely seen (4.4%). No external stress shielding or osteolysis was observed. Thirty-six complications occurred in 33 patients (15.1%). At an average follow-up of 36.6 months, significant improvements were identified in all measured clinical outcomes (P < .001).

CONCLUSION

Predictable fixation is achieved using an adjustable diaphyseal press-fit humeral system in primary RSA. Internal stress shielding is commonly observed but does not appear to compromise quality of fixation or clinical outcomes.

One-stage exchange of septic shoulder arthroplasty following a standardized treatment algorithm

BACKGROUND

Studies on 1-stage exchange in septic shoulder arthroplasty are limited and show a wide variation of treatment strategies. This retrospective study investigated infection-free survival and function of 1-stage exchange of septic shoulder arthroplasty following a standardized treatment algorithm.

METHODS

The requirement for 1-stage exchange was an isolated microorganism from synovial fluid aspiration or synovial biopsy with an antibiotic susceptibility profile prior to revision surgery. If no microorganism was isolated or the underlying pathogen was a difficult-to-treat microorganism (not accessible for biofilm-active antibiotics, enterococci, and fungi), 2-stage exchange was performed. Function was assessed by the Constant score.

RESULTS

Fourteen patients were included, with a mean follow-up period of 5.8 years. The most and second most commonly detected microorganisms were Cutibacterium acnes (formerly Propionibacterium acnes), and Staphylococcus epidermidis, respectively. At 1-stage exchange, patients received local and systemic antibiotics based on the susceptibility profile of the microorganism. Twelve patients with insufficient rotator cuffs received reverse shoulder arthroplasty, whereas 2 patients with intact rotator cuffs underwent anatomic total shoulder arthroplasty. The infection-free survival rate at 1 and 5 years was 100% and 93% (95% confidence interval [CI], 59%-99%), respectively, with 1 recurrence of infection 22 months after 1-stage exchange. Another patient with limited range of motion underwent revision 6 months postoperatively, leading to a revision-free survival rate of 93% (95% CI, 59%-99%) and 86% (95% CI, 54%-96%) at 1 and 5 years, respectively. The mean Constant score was 65 (range, 44-95).

CONCLUSION

One-stage exchange with prior detection of the underlying microorganism provides satisfactory infection-free survival and function.

One- and two-stage surgical revision of infected shoulder prostheses following arthroplasty surgery: A systematic review and meta-analysis

Periprosthetic joint infection (PJI) is a catastrophic complication of shoulder arthroplasty. Commonly used surgical treatments include one- or two-stage revision, but their effectiveness in controlling infection is uncertain. We aimed to compare re-infection (recurrent and new infections) rates; clinical measures of function and pain; and noninfection complication rates of one- and two-stage revision surgery for shoulder PJI using a systematic review and meta-analysis. We searched MEDLINE, Embase, Web of Science, and The Cochrane Library to February 2018. Longitudinal studies conducted in patients with shoulder PJI treated exclusively by one- or two-stage revision were eligible. No clinical trials were identified. Re-infection rates were meta-analysed using random-effect models after arcsine transformation. The re-infection rate (95% CI) in pooled analysis of eight one-stage studies (147 participants) was 5.3% (1.4-10.6). The corresponding rate for 27 two-stage studies (351 participants) was 11.5% (6.0-18.1). Postoperative clinical measures of function and pain were not significantly different between the two revision strategies. The pooled noninfection complication rate (95% CI) for one-stage and two-stage revision was 12.1% (6.1-19.5) and 18.9% (8.4-31.9) respectively. New evidence suggests one-stage revision is at least equally as effective as the two-stage in controlling infection, maintaining joint function, and improving complications in shoulder PJI.

Pyrocarbon interposition shoulder arthroplasty in young arthritic patients: a prospective observational study

BACKGROUND

We evaluated survival and midterm results of pyrocarbon interposition shoulder arthroplasty (PISA) in arthritic patients younger than 65 years.

METHODS

Fifty-eight PISAs (InSpyre; Tornier-Wright, Bloomington, MN, USA), implanted in 56 patients between 2010 and 2015, were prospectively observed. The mean age at surgery was 52 ± 13 years. The cause was primary osteoarthritis (18), fracture sequelae (16), post-instability arthritis (15), aseptic necrosis (3), inflammatory disease (2), and failed hemiarthroplasty (4); 34 shoulders (61%) had previously undergone surgery. Glenoid erosion was assessed in 4 grades according to the Sperling classification. Humeral erosion was also assessed in 4 grades. Multivariate analysis was used to determine predisposing risk factors for both humeral and glenoid erosion.

RESULTS

At a mean follow-up of 47 ± 15 months, survival rate was 90%. Six patients (10%) required conversion to reverse total shoulder prosthesis for painful glenoid erosion (n = 2) and humeral erosion with greater tuberosity stress fractures (n = 4). The mean Constant score and subjective shoulder value significantly increased from 36 ± 14 points to 70 ± 15 points and 32% ± 14% to 75% ± 19%, respectively (P < .001). Humeral medialization was observed in 78% of the cases with increased pain score. Uncorrected anteroposterior implant subluxation (12 cases) was associated with lower Constant score (50 points vs. 72 points; P = .02) and lower subjective shoulder value (53% vs. 78%; P = .002). On multivariate analysis, no risk factors for glenoid or humeral erosion were found.

CONCLUSION

At midterm follow-up, PISA does not protect from progressive glenoid erosion and can lead to greater tuberosity erosion and stress fractures. Longer follow-up is required to see whether PISA survival will be superior to that of hemiarthroplasty.

Labeled white blood cell/bone marrow single-photon emission computed tomography with computed tomography fails in diagnosing chronic periprosthetic shoulder joint infection

BACKGROUND

Shoulder periprosthetic joint infections (PJI) caused by low-virulent bacteria pose a diagnostic challenge. Combined labeled leukocyte (WBC) and technetium 99m sulfur colloid bone marrow imaging (WBC/BM) is considered the radionuclide imaging gold standard for diagnosing lower limb PJI. However, it is laborious and expensive to perform, and documentation on shoulder arthroplasties is lacking. This study investigated WBC/BM single-photon emission computed tomography-computed tomography diagnostic performance in shoulder PJI.

METHOD

All patients with a failed arthroplasty referred to a highly specialized shoulder department were scheduled for a diagnostic program including a WBC/BM. If an arthroplasty was revised, biopsy specimens were obtained and cultured for 14 days. The diagnostic performance of WBC/BM imaging was determined using biopsy specimens as a reference.

RESULTS

Of the 49 patients who underwent a WBC/BM scan, 29 (59%) were revised. Infection was present in 11 patients, in whom 2 WBC/BM scans were true positive. The WBC/BM scan in 9 patients was false negative. The remaining 18 patients all had a true negative WBC/BM scan. WBC/BM showed a sensitivity 0.18 (95% confidence interval [CI], 0.00-0.41) and specificity 1.00 (95% CI, 1.00-1.00) in detecting shoulder PJI. The positive predictive value was 1.00 (95% CI, 1.00-1.00), and negative predictive value was 0.67 (95% CI, 0.49-0.84). No patients infected with Cutibacterium (formerly Propionibacterium) acnes resulted in a positive WBC/BM, nor had they preoperative or perioperative signs of infection.

CONCLUSION

A positive WBC/BM was found only in patients with obvious PJI. Hence, the scan added nothing to the preoperative diagnosis. The WBC/BM single-photon emission computed tomography-computed tomography scan cannot be recommended as a screening procedure when evaluating failed shoulder arthroplasties for possible infection.

Diagnostic Arthroscopy for Detection of Periprosthetic Infection in Painful Shoulder Arthroplasty

PURPOSE

To analyze the utility of arthroscopic biopsies for detection of periprosthetic infection in painful shoulder arthroplasty without objective signs of infection.

METHODS

A retrospective analysis of all patients who underwent a diagnostic arthroscopy for painful shoulder arthroplasty from June 2012 through July 2018 was performed. Patients with a subsequent revision shoulder arthroplasty after diagnostic arthroscopy were included. Arthroscopic tissue culture results were compared with the culture results of intraoperative tissue samples obtained at the time of open revision surgery. A minimum of 3 tissue samples from synovia and bone-prosthesis interface with signs of synovitis or abnormal appearance was routinely collected. Cases with 2 or more positive cultures for the same microorganism obtained at open revision surgery were considered as true presence of infection. The study protocol was reviewed and approved by the institutional ethics committee.

RESULTS

Twenty-three cases in 22 patients were included in this study. Five of these 23 cases were classified as true infection based on the samples obtained during open revision surgery, and 16 cases had a positive culture in diagnostic arthroscopy. Cutibacterium acnes was isolated in each case. Classifying any microbiologic growth in the arthroscopic biopsies as positive resulted in a sensitivity and negative predictive value of 100%, specificity of 39%, and positive predictive value of 31.3% for the detection of a periprosthetic shoulder infection (PPSI). If at least 2 positive samples with the same microbiologic growth in the arthroscopic biopsies were considered as positive, sensitivity and negative predictive value dropped to 80% and 94.4%, respectively, but the specificity and positive predictive value increased to 94.4% and 80%, respectively.

CONCLUSIONS

Diagnostic arthroscopy is a useful diagnostic tool in patients with suspicion but no clear evidence of PPSI. Arthroscopically obtained tissue biopsies for culture offer a high sensitivity and specificity in the diagnosis of PPSI if at least 2 cultures positive for the same microorganism are considered as infection.

LEVEL OF EVIDENCE

Level III.

Glenoid component lucencies are associated with poorer patient-reported outcomes following anatomic shoulder arthroplasty

BACKGROUND

High rates of radiographic glenoid loosening following anatomic total shoulder arthroplasty (TSA) are documented at midterm follow-up. Small studies remain conflicted on the impact of lucent lines on clinical outcomes. This study assesses the impact of radiolucent lines on function and patient-reported outcomes (PROs) following TSA.

METHODS

We retrospectively evaluated 492 primary TSAs performed between February 2005 and April 2016. Radiographs were evaluated for glenoid loosening according to the Lazarus grade at a mean of 5.3 years (range, 2-12 years). Clinical outcome measures included range of motion and American Shoulder and Elbow Surgeons, Constant, University of California-Los Angeles, Simple Shoulder Test, and Shoulder Pain and Disability Index scores. Outcomes were compared between patients with and patients without glenoid lucent lines and in relation to lucency grade.

RESULTS

At most recent follow-up, 308 glenoids (63%) showed no radiolucent lines (group 0) and 184 demonstrated peri-glenoid lucencies (group 1). The groups were similar regarding age, sex, body mass index, comorbidities, and prior surgery. At follow-up, group 1 demonstrated significantly lower improvements in forward elevation (P = .02) and all PROs (P ≤ .005). Subgroup analysis by radiolucency grade showed that forward elevation diminished with increasing radiolucent score and exceeded the minimal clinically important difference (MCID) above grade 2 lucencies. A similar decline in PROs was observed with increasing lucency grade. These differences did not exceed the MCID below grade 5 lucencies.

DISCUSSION

Peri-implant glenoid lucencies following TSA are associated with lower forward elevation and PROs. Lucencies above grade 2 are associated with clinically important losses in overhead motion. However, differences below the MCID are maintained for PROs below grade 5 glenoid lucencies.

Novel exploration of customized 3D printed shoulder prosthesis in revision of total shoulder arthroplasty: A case report

RATIONALE

This paper describes the application of individual customized 3-dimensional (3D) printed macro-porous Ti6Al4 V shoulder prosthesis in the revision of total shoulder arthroplasty (TSA) for the patient with severe bone defects.

PATIENT CONCERNS

A 47-year-old male had been under proximal humeral resection and TSA due to shoulder chondrosarcoma 6 years ago, but a second surgery to insert a new prosthesis was then performed because the prosthesis became loose 2 months ago leaving severe bone defects which conventional prosthesis was not suitable for revision of TSA. American Shoulder and Elbow Surgeons' Form (ASES), Neer and Constant-Murley score were 36, 39, and 39, respectively.

DIAGNOSES

The patient was diagnosed with shoulder bone defects and restriction of the shoulder movement.

INTERVENTIONS

3D printed shoulder model and computer-aided design (CAD) were used for prosthesis design and surgical simulation. The novel 3D printed titanium alloy shoulder prosthesis was customized subsequently to be used in the revision of TSA. The patient was followed up regularly after surgery. The ASES, Neer Shoulder score and Constant-Murley Shoulder score were evaluated during pre-operation, post-operation, and follow-up.

OUTCOMES

Prosthesis was successfully implanted to complete anatomic reconstruction intraoperatively. The scores of ASES, Neer, and Constant-Murley were gradually increased after the operation. According to the X-ray, the bone healed satisfactorily without change of prosthetic position at 3rd and 12th months after the operation. The function of shoulder could meet the requirements of daily activities.

LESSONS

The application of customized 3D printed titanium alloy shoulder prosthesis in the revision of TSA achieves satisfactory results. It provides a novel method for the similar revision surgery with severe bone defects.

Validation of a new classification for periprosthetic shoulder fractures

INTRODUCTION

Successful treatment of periprosthetic shoulder fractures depends on the right strategy, starting with a well-structured classification of the fracture. Unfortunately, clinically relevant factors for treatment planning are missing in the pre-existing classifications. Therefore, the aim of the present study was to describe a new specific classification system for periprosthetic shoulder fractures including a structured treatment algorithm for this important fragility fracture issue.

METHODS

The classification was established, focussing on five relevant items, naming the prosthesis type, the fracture localisation, the rotator cuff status, the anatomical fracture region and the stability of the implant. After considering each single item, the individual treatment concept can be assessed in one last step. To evaluate the introduced classification, a retrospective analysis of pre- and post-operative data of patients, treated with periprosthetic shoulder fractures, was conducted by two board certified trauma surgery consultants.

RESULTS

The data of 19 patients (8 male, 11 female) with a mean age of 74 ± five years have been analysed in our study. The suggested treatment algorithm was proven to be reliable, detected by good clinical outcome in 15 of 16 (94%) cases, where the suggested treatment was maintained. Only one case resulted in poor outcome due to post-operative wound infection and had to be revised.

CONCLUSIONS

The newly developed six-step classification is easy to utilise and extends the pre-existing classification systems in terms of clinically-relevant information. This classification should serve as a simple tool for the surgeon to consider the optimal treatment for his patients.

Proceedings from the 2018 International Consensus Meeting on Orthopedic Infections: management of periprosthetic shoulder infection

The Second International Consensus Meeting on Orthopedic Infections was held in Philadelphia, Pennsylvania, in July 2018. A multidisciplinary team of international experts from all 9 subspecialties of orthopedic surgery and allied fields of infectious disease, microbiology, and epidemiology was assembled to form the International Consensus Group. The following consensus proceedings from the International Consensus Meeting involve 30 questions pertaining to the management of periprosthetic shoulder infection.

Novel in vivo mouse model of shoulder implant infection

BACKGROUND

Animal models are used to guide management of periprosthetic implant infections. No adequate model exists for periprosthetic shoulder infections, and clinicians thus have no preclinical tools to assess potential therapeutics. We hypothesize that it is possible to establish a mouse model of shoulder implant infection (SII) that allows noninvasive, longitudinal tracking of biofilm and host response through in vivo optical imaging. The model may then be employed to validate a targeting probe (1D9-680) with clinical translation potential for diagnosing infection and image-guided débridement.

METHODS

A surgical implant was press-fit into the proximal humerus of c57BL/6J mice and inoculated with 2 μL of 1 × 103 (e3), or 1 × 104 (e4), colony-forming units (CFUs) of bioluminescent Staphylococcus aureus Xen-36. The control group received 2 μL sterile saline. Bacterial activity was monitored in vivo over 42 days, directly (bioluminescence) and indirectly (targeting probe). Weekly radiographs assessed implant loosening. CFU harvests, confocal microscopy, and histology were performed.

RESULTS

Both inoculated groups established chronic infections. CFUs on postoperative day (POD) 42 were increased in the infected groups compared with the sterile group (P < .001). By POD 14, osteolysis was visualized in both infected groups. The e4 group developed catastrophic bone destruction by POD 42. The e3 group maintained a congruent shoulder joint. Targeting probes helped to visualize low-grade infections via fluorescence.

DISCUSSION

Given bone destruction in the e4 group, a longitudinal, noninvasive mouse model of SII and chronic osteolysis was produced using e3 of S aureus Xen-36, mimicking clinical presentations of chronic SII.

CONCLUSION

The development of this model provides a foundation to study new therapeutics, interventions, and host modifications.

Two-stage revision of infected shoulder arthroplasty using prosthesis of antibiotic-loaded acrylic cement: minimum three-year follow-up

PURPOSE

This study aimed to evaluate the clinical outcomes and persistent infection rate of two-stage revision of infected shoulder arthroplasty.

METHODS

We enrolled 12 patients who developed an infection after undergoing shoulder arthroplasty between January 2009 and January 2014. They underwent a two-stage revision with PROSTALAC implantation and shoulder re-implantation in the first- and second-stage surgery, respectively. The mean follow-up period was 40.88 months (range, 36-52 months). After the second-stage re-implantation, clinical scores, erythrocyte sedimentation rate, as well as C-reactive protein level were evaluated, and the presence of re-infection and complications were analyzed.

RESULTS

Infection was improved in all the cases after PROSTALAC insertion. The mean range of motion of forward elevation, external rotation, and internal rotation at the final follow-up after the second-stage re-implantation were 81.67°, 40.42°, and 16.67° (vertebral level), respectively. The mean visual analog scale score improved from 7.08 points before surgery to 2.33 points after surgery. The Modified American Shoulder and Elbow Surgeons score improved from 32.25 before surgery to 64.17 after surgery (P < 0.05). The Constant shoulder score also improved from 30.92 before surgery to 66.08 after surgery (P < 0.05). Infection had not recurred until the final follow-up. However, dislocation and separation of components were found in two patients who needed a structural allograft because of segmental bone defects.

CONCLUSION

Using PROSTALAC in two-stage revision arthroplasty is effective for infection control and produced good clinical outcomes after second-stage shoulder re-implantation. However, cases involving segmental bone defects require additional precautions in maintaining the appropriate tension and height to prevent complications.

Proceedings from the 2018 International Consensus Meeting on Orthopedic Infections: prevention of periprosthetic shoulder infection

The Second International Consensus Meeting on Orthopedic Infections was held in Philadelphia, Pennsylvania, in July 2018. Over 800 international experts from all 9 subspecialties of orthopedic surgery and allied fields of infectious disease, microbiology, and epidemiology were assembled to form a consensus workgroup. The following proceedings on the prevention of periprosthetic shoulder infection come from 16 questions evaluated by delegates from the shoulder section.

The relationship between glenoid inclination and instability following primary reverse shoulder arthroplasty

PURPOSE

Despite advances in implant design and surgical technique, instability remains the most common early complication and reason for early revision after reverse shoulder arthroplasty (RSA). The purpose of this study is to evaluate the glenoid implant inclination, as measured by the β-angle, as an independent risk factor for instability after primary RSA.

METHODS

A retrospective case-control study was conducted matching cases with instability after primary RSA using a single implant to controls without instability. Controls were matched to age, sex, body mass index, and baseplate type (1:3 ratio of cases to controls). The preoperative, postoperative, and the change in pre- to postoperative glenoid inclination (β-angle) were compared between groups.

RESULTS

Thirty-four cases (mean age, 66.2 years) were matched to 102 controls (mean age, 67.0 years). There was a wide range of postoperative (63° to 100°) and pre- to postoperative change (-16.5° to +30.5°) in β-angles collectively. There was no significant difference in the postoperative β-angle (mean, 80.8° vs. 82.7°, P = .19) or the change in β-angle (mean, +1.7° vs. +3.4°, P = .35) between cases and controls, respectively. Regression analysis demonstrated no increased odds of instability with the postoperative β-angle, odds ratio 0.965 (confidence interval [CI] = 0.916-1.02, P = .19). Likewise, for the preoperative to postoperative change in β-angle, there was no significantly increased odds of instability, odds ratio 0.978 (CI = 0.934-1.03, P = .35). Finally, there was no difference in risk of instability in patients whose implant positioning resulted in a net superior increase in inclination, relative risk 0.85 (95% CI = 0.46-1.56, P = .28).

CONCLUSIONS

Neither the final prosthetic glenoid inclination nor the change in glenoid inclination, as measured by the β-angle, significantly influences the risk of prosthetic instability after primary RSA.

Mid-term results with an anatomic stemless shoulder prosthesis in patients with primary osteoarthritis

OBJECTIVE

The introduction of a stemless prosthesis in shoulder arthroplasty represents a novel design whereby the proximal humerus is restored anatomically, while leaving the diaphysis of the humerus untouched. The aim of this study was to present the mid-term results of total evolutive shoulder system (TESS; Biomet^®), a stemless shoulder prosthesis.

METHODS

The study included 38 consecutive patients (18 men and 20 women; mean age: 66 years; range: 55-81 years) treated with shoulder arthroplasty between 2009 and 2011 with TESS for primary glenohumeral arthritis. Total shoulder arthroplasty (TSA) was performed in 28 cases (74%), hemi-shoulder arthroplasty (HSA) in 10 (26%). Constant score, active range of motion, patient satisfaction rate, and radiological assessment were analyzed. Mean time of follow-up was 37 months.

RESULTS

Constant score improved from 21.8 points (28.6 adjusted for age) preoperatively to 74.1 points (86.6 adjusted for age) postoperatively. Active range of motion increased significantly from the pre- to postoperative status. Eighty-nine percent were very satisfied or satisfied with shoulder replacement surgery. One cemented glenoid was revised due to aseptic loosening. None of the components were found to be loose at the final follow-up. No signs of stress shielding were seen.

CONCLUSIONS

This study shows promising results of this implant concept in the short- to mid-term. These results are comparable with the results achieved with long-established arthroplasty designs.

LEVEL OF EVIDENCE

Level IV, Therapeutic Study.

Early rehabilitation after reverse total shoulder prosthesis on fracture of proximal humerus in elderly patients provides better functional outcome

PURPOSE

Reverse total shoulder arthroplasty (RSA) has revolutionized the management of proximal humerus fractures (PHF) in the elderly patients. There is few or no consensus regarding to management of postoperative rehabilitation in elderly patients. An early rehabilitation from D1 allowed better functional results compared to rehabilitation started to D30 independently from tuberosities consolidation.

METHODS

94 patients operated on for PHF were evaluated retrospectively, with a minimum radio-clinical follow-up of 2 years. Clinical evaluation included mobilities and four functional scores: ASES, quick DASH, gross constant, weighted constant. Radiological evaluation was performed on a frontal shoulder X-ray with evaluation of tuberosities' consolidation.

RESULTS

The mean follow-up was 45 ± 19 months (24-88 months). Early rehabilitation was significantly associated with a better Constant Score (71.1 ± 17.2 vs. 56.4 ± 15.8; p < 0.001), better adjusted Constant score (92.4 ± 14.2 vs. 80.3 ± 19.5; p < 0.001), better quick DASH (22.8 ± 19.8 vs. 36.7 ± 21.3; p < 0.01), better ASES (78.6 ± 20.2 vs. 63 ± 22; p < 0.001).

CONCLUSION

In traumatology, functional result of RSA seems not related in tuberosities' union but in rehabilitation in order to limit postoperative stiffness of operated shoulder. An early rehabilitation is related with better clinical and functional results, independently of tuberosities' union.

LEVEL OF EVIDENCE

3, control-case study.

Is D-dimer a Reliable Serum Marker for Shoulder Periprosthetic Joint Infection?

BACKGROUND

The diagnosis of periprosthetic shoulder infection continues to be difficult to make with confidence. Serum D-dimer has proven to be effective as a screening tool for periprosthetic joint infection in other major joints; however, it has yet to be evaluated for use in periprosthetic shoulder infection.

QUESTIONS/PURPOSES

(1) Is D-dimer elevated in patients with probable or definite periprosthetic shoulder infections? (2) What is the diagnostic accuracy of D-dimer for periprosthetic shoulder infections? (3) What are the diagnostic accuracies of serum tests (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], and D-dimer), singly and in combination?

METHODS

Between March 2016 and March 2020, 94 patients undergoing revision total shoulder arthroplasty (anatomic or reverse) at a single institution had preoperative serum testing with CRP, ESR, and D-dimer. These 94 patients were a subset of 189 revision shoulder arthroplasties performed at this institution during the study period who met inclusion criteria and consented to participate. Included patients had a mean ± SD age of 69 ± 8 years, and 56% (53 of 94) were men. Patient records were reviewed to classify patients as definitely having infection, probably having infection, possibly having infection, or unlikely to have an infection, according to the International Consensus Meeting (ICM) definition of periprosthetic shoulder infection. Statistical analyses, including a receiver operating characteristic curve analysis, were performed to quantify the diagnostic value of D-dimer for periprosthetic shoulder infection. Based on the ICM definition, 4% (4 of 94), 15% (14 of 94), 14% (13 of 94), and 67% (63 of 94) of patients had definite, probable, possible, or unlikely periprosthetic shoulder infections.

RESULTS

D-dimer was elevated in patients with definite or probable infections (median [range] 661 ng/mL [150 to 8205]) compared with those with possible infections or those who were unlikely to have an infection (263 ng/mL [150 to 3060]; median difference 143 ng/mL [95% CI 40 to 503]; p = 0.01). In the receiver operating characteristic curve analysis, D-dimer had an area under the curve of 0.71 (0.50-0.92), demonstrating weak diagnostic value. A D-dimer level of 598 ng/mL provided a sensitivity and specificity of 61% (95% CI 36% to 82%) and 74% (95% CI 62% to 83%), respectively, for diagnosing a definite or probable infection according to the ICM definitions. The specificity of detecting periprosthetic joint infection (88% [95% CI 79% to 94%]) was high when three positive serum markers (ESR, CRP, and D-dimer) were required, at the expense of sensitivity (28% [95% CI 10% to 53%]).

CONCLUSION

In periprosthetic shoulder infection, D-dimer is elevated. However, similar to other serum tests, it has limited diagnostic utility in identifying patients with periprosthetic shoulder infection. Further work is needed to understand the process by which D-dimer is associated with active infection.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Polyethylene dissociation from humeral stem status after reverse total shoulder arthroplasty

BACKGROUND

Reverse shoulder arthroplasty (RSA) is an important treatment option for 4-part proximal humerus fractures in the elderly and arthrosis of the glenohumeral joint with incompetence of the rotator cuff. Unique complications do occur with use of this type of prosthesis.

METHODS

We present 4 cases of polyethylene dissociation after RSA.

RESULTS

In a series of 549 patients who underwent RSA, the incidence of polyethylene dissociation was found to be 0.7%.

CONCLUSIONS

Polyethylene dissociation is a rare complication after RSA. Surgeons should be aware of this possibility if a closed reduction of an RSA dislocation is not possible.

Comparison of stemless and conventional stemmed shoulder arthroplasties in shoulder arthropathy: A meta-analysis

BACKGROUND

It is unclear whether stemless shoulder prosthesis lead to better clinical outcomes than conventional stemmed shoulder prosthesis. The purpose is to compare clinical outcomes and complication rates after surgery in patients with shoulder arthropathy treated with stemless or conventional stemmed shoulder prosthesis.

METHOD

All studies comparing the constant score (CS), range of motion (ROM), and complication rates after surgery in patients with shoulder arthropathy treated with stemless or conventional stemmed shoulder prosthesis were included. The major databases MEDLINE, EMBASE, the Cochrane Library, Web of Science, and SCOPUS were searched for appropriate studies from the earliest available date of indexing through March 31, 2019. No restrictions were placed on language of publication.

RESULTS

A total of 6 studies met the inclusion criteria and were analyzed in detail. Overall postoperative ROM (95% CI: 3.27 to 11.92; P < .01) was significantly greater for stemless prosthesis compared to conventional stemmed prosthesis. However, postoperative CS (95% CI: -2.98 to 7.13; P = .42) and complication rates (OR 1.22, 95% CI: 0.48-3.08; P = .68) were did not differ significantly between the 2 groups.

CONCLUSION

This meta-analysis revealed that postoperative CS and complication rates did not differ significantly between the 2 treatment methods, stemless shoulder prosthesis and conventional stemmed shoulder prosthesis, for shoulder arthropathy. However, stemless shoulder prosthesis resulted in better outcomes than conventional stemmed shoulder prosthesis in terms of postoperative ROM.

LEVEL OF EVIDENCE

Level III, Therapeutic study.

Polyethylene Liner Dissociation after Reverse Shoulder Arthroplasty Dislocation: a Case Series

Reverse shoulder arthroplasty is a common procedure. While dislocation is a common complication, there are few reports documenting dislocation with associated polyethylene liner dissociation from the humeral tray. There have been 4 instances of this occurrence over 9 years at our institution, and there are specific radiographic clues for diagnosis. Recognizing polyethylene liner dissociation on imaging is important prior to treatment. In a "routine" dislocation, closed reduction may be attempted but when the polyethylene is dissociated, open reduction is the only treatment option, as closed reduction can damage the components. Dislocations with polyethylene dissociation may not be initially recognized, prompting a non-operative period leading to wear and metallosis. These 4 cases demonstrate key findings present on imaging to recognize the difference between a dislocation with and without polyethylene liner dissociation, namely the subluxation appearance rather than dislocation.

Assessment of intraoperative bleeding in reverse shoulder arthroplasty - with or without a stem

INTRODUCTION

The functional results of stemless reverse shoulder prostheses are similar to those with stems. However, the operative time and the bleeding appear less significant because of the absence of humeral reaming. To date, the data amongst the literature regarding this subject is limited. Thus, we report a retrospective evaluation on these 2 types of prostheses by assessing their respective intraoperative blood loss.

HYPOTHESIS

Reverse shoulder arthroplasty without a stem leads to less blood loss, compared to arthroplasty with a stem.

MATERIALS AND METHODS

Twenty-three patients underwent an operation for a stemless prosthesis, while 37 patients had a prosthesis with a stem. The hemoglobin was measured preoperatively, as well as postoperatively. Drainage of the operative site was maintained for two to three days. In the stem group, the preoperative hemoglobin was 14g/dL (11.7-16.6), while it was 13.1g/dL (11-15.8) in the stemless group.

RESULTS

The intraoperative bleeding reached 223cm³ (80-530), with an operative duration of 81minutes (40-110) in the stemless group, compared to 260cm³ (50-1000) and 92minutes (33-110) in the stem group. On the first day postoperatively, 333cm³ (20-570) of blood had been collected by drainage for the stemless group, compared to 279cm³ (40-550) in the stem group. The amount decreased the second day, with 139cm³ (20-510) and 129cm³ (0-750) respectively. There was no difference between the two groups regarding the postoperative hemoglobin level (11g/dL).

DISCUSSION

There is no significant difference concerning the blood loss between reverse shoulder replacements with and without stems.

LEVEL OF EVIDENCE

III Retrospective case control study.