Reverse shoulder prosthesis in patients with rheumatoid arthritis: a systematic review

Comparison of reverse shoulder arthroplasty and total shoulder arthroplasty for patients with inflammatory arthritis

BACKGROUND

End-stage glenohumeral joint arthritis is common in patients with inflammatory arthritis. Reverse shoulder arthroplasty (RSA) and anatomic total shoulder arthroplasty (TSA) are both indicated in this setting. RSA is often considered based on the impacts of long-standing inflammatory arthritis including glenoid and humeral bone erosion and rotator cuff insufficiency. However, acromial and scapular spine fractures following RSA have been reported more commonly in these patients, which can have a significant impact on outcomes. Currently, no study has directly compared the efficacy and complication rates of RSA vs. TSA in patients with inflammatory arthritis. This study aimed to investigate differences in clinical outcomes and complications in patients undergoing RSA vs. TSA with glenohumeral inflammatory arthritis.

METHODS

We performed a retrospective review of 86 patients with inflammatory arthritis treated with primary RSA (n = 43) or TSA (n = 43) with a minimum of 2 years' follow-up. American Shoulder and Elbow Surgeons scores, Simple Shoulder Test scores, visual analog scale scores for pain and function, active range of motion, and patient self-ratings of upper-extremity normality (Subjective Assessment of Normal Evaluation [SANE]) were collected preoperatively and at minimum 2-year follow-up. Radiographic classification of preoperative glenoid and humeral bone loss was performed, and postoperative complications were observed. Revision and complication details were compared.

RESULTS

The study cohort had an average age of 72.1 years (range, 31-92 years) and average follow-up period of 51.6 months (range, 22-159 months). Both the RSA and TSA cohorts demonstrated improvements in patient-reported outcome measures and ranges of motion; however, patients treated with TSA showed a greater postoperative final Simple Shoulder Test score (P < .001), visual analog scale score for function (P = .0347), active elevation (P = .0331), active external rotation (P < .001), active internal rotation (P = .005), and Single Assessment Numeric Evaluation (SANE) score (P = .0161). Analysis of complication rates demonstrated no statistically significant difference between cohorts. Four acromial fractures occurred in the RSA group. When RSA patients who sustained acromial fractures were removed from the analysis, there were minimal differences in outcomes between the RSA and TSA cohorts.

CONCLUSION

TSA in patients with inflammatory arthritis leads to improved clinical outcomes but higher early revision rates when compared with RSA. RSA outcomes are negatively impacted by a high rate of postoperative acromial fractures.

The impact of Charlson and Elixhauser comorbidities on patient outcomes following shoulder arthroplasty

AIMS

To investigate the impact of the Charlson and Elixhauser comorbidity indices on patient-reported outcomes measures (PROMs) following shoulder arthroplasty.

METHODS

Patients undergoing total shoulder arthroplasty (TSA), reverse shoulder arthroplasty (RSA), or hemiarthroplasty (HA) from 2016 to 2018 were identified, along with the Charlson and Elixhauser comorbidities listed as their secondary diagnoses in the electronic medical records. Patients were matched to our institution's registry to obtain their PROMs, including shoulder-specific (American Shoulder and Elbow Society (ASES) and Shoulder Activity Scale (SAS)) and general health scales (12-Item Short Form Survey (SF-12) and Patient-Reported Outcomes Measurement Information System-Pain Interference). Linear regression models adjusting for age and sex were used to evaluate the association between increasing number of comorbidities and PROM scores. A total of 1,817 shoulder arthroplasties were performed: 1,017 (56%) TSA, 726 (40%) RSA, and 74 (4%) HA. The mean age was 67 years (SD 10), and 936 (52%) of the patients were female.

RESULTS

The most common comorbidities were obesity (1,256, 69%) and hypertension (990, 55%). Patients with more comorbidities had lower ASES and SAS scores at baseline (p < 0.001). Elixhauser comorbidities continued to negatively impact ASES and SAS scores at one year (p = 0.002) and two-year follow-up (p = 0.002). Patients with more comorbidities reported greater pain interference on PROMIS at baseline (p = 0.007), but not at two years. Higher number of Charlson comorbidities were associated with lower scores on the SF-12 mental component at baseline (p < 0.001) and two years (p = 0.020). Higher number of Elixhauser comorbidities were associated with lower SF-12 physical component scores at baseline (p < 0.001) and two years (p = 0.004).

CONCLUSION

Higher number of comorbidities was associated with lower baseline scores and worse outcomes on both shoulder-specific and general health PROMs. The presence of specific comorbidities may be used during shared decision-making to manage expectations for patients undergoing shoulder arthroplasty. Cite this article: Bone Joint J 2021;103-B(5):964-970.

Outcome of a metaphyseal reverse total shoulder replacement in rheumatoid arthritis

AIM

To assess the clinical and radiological results of a metaphyseal reverse total shoulder arthroplasty (rTSA) without diaphyseal stem, in rheumatoid arthritis (RA) patients.

METHODS

Forty-five shoulders in 36 consecutive RA patients (2005-2015) underwent rTSA with a bone impaction technique. Patients were assessed clinically and radiographically preoperatively, at 3 weeks, 3 months, 6 months, 12 months post-operatively, and yearly thereafter, using constant score (CS), pain score, subjective shoulder value (SSV) and patient satisfaction score.

RESULTS

Forty-four shoulders with mean follow-up of 67 months (range 24 m-146 m (12y)) were available for follow-up. Mean age at surgery was 68.7 years (range 39-86). CS improved from 17.5 ± 10.5(SD) (age/sex adjusted 23.9 ± 14.5(SD)) preoperatively to 60.9 ± 17.4 (SD) (age/sex adjusted 86.5 ± 24.5 (SD)) at last follow-up (P < 0.001). Pain score and SSV also significantly improved (p < 0.001). Mean range of movement improved to 140°active forward flexion, 134°active abduction, 47°active external rotation (AER) and 70°active internal rotation (AIR). The results were maintained over time. Combined early and late complication rate was 15.6%, which is lower than described in the literature for RA. No lucencies, loosening, subsidence or stress shielding were evident radiographically.

CONCLUSION

Metaphyseal rTSA without a diaphyseal stem is successful and safe in RA patients. Patients achieve good function and have high satisfaction rates.

LEVEL OF EVIDENCE

Case series: Level IV.

Midterm clinical outcomes of reverse shoulder arthroplasty in Japanese patients with rheumatoid arthritis using patient-reported outcome measures (Shoulder36)

Background

Reverse shoulder arthroplasty normally has adequate functional outcomes in patients with cuff tear arthropathy. The present study aimed to investigate the midterm clinical outcomes of reverse shoulder arthroplasty in Japanese patients with rheumatoid arthritis.

Methods

Between July 2014 and May 2016, reverse shoulder arthroplasty was performed in 14 rheumatic shoulders with joint destruction and rotator cuff tears. The range of motion, Constant score, and Shoulder36, which is a patient-reported outcome measure, were compared preoperatively and postoperatively. The prevalence of subscapular notching, subscapular osteophytes, postoperative fractures, and stress shielding of the humeral stem were evaluated by X-ray.

Results

Range of motion significantly improved from 77 to 122 degrees in flexion and from 67 to 111 degrees in abduction at four years. The Constant score significantly improved from 27 to 62, and each domain of Shoulder36 also significantly increased at four years. There was no dislocation, infection, or loosening of the prosthesis. Three shoulders presented scapular notching, and three cemented humeral stems showed stress shielding in the proximal humeral cortical bone.

Conclusion

Reverse shoulder arthroplasty performed in Japanese patients with rheumatoid arthritis not only decreased the pain and improved the function of the shoulder joint but also significantly improved patients' health and activity of daily living in midterm results.

Assessment of surgeon variability in preoperative planning of reverse total shoulder arthroplasty: a quantitative comparison of 49 cases planned by 9 surgeons

BACKGROUND

Preoperative planning software is gaining utility in reverse total shoulder arthroplasty (RTSA), particularly when addressing pathologic glenoid wear. The purpose of this study was to quantify inter- and intrasurgeon variability in preoperative planning a series of RTSA cases to identify differences in how surgeons consider optimal implant placement. This may help identify opportunities to establish consensus when correlating plan differences with clinical data.

METHODS

A total of 49 computed tomography scans from actual RTSA cases were planned for RTSA by 9 fellowship-trained shoulder surgeons using the same platform (Exactech GPS, Exactech Inc., Gainesville, FL, USA). Each case was planned a second time 6-12 weeks later. Variability within and between surgeons was measured for implant selection, version correction, inclination correction, and implant face position. Interclass correlation coefficients, and Pearson and Light's kappa coefficient were used for statistical analysis.

RESULTS

There was considerable variation in the frequency of augmented baseplate selection between surgeons and between rounds for the same surgeon. Thresholds for augment use also varied between surgeons. Interclass correlation coefficients for intersurgeon variability ranged from 0.43 for version, 0.42 for inclination, and 0.25 for baseplate type. Pearson coefficients for intrasurgeon variability were 0.34 for version and 0.30 for inclination. Light's kappa coefficient for baseplate type was 0.61.

CONCLUSIONS

This study demonstrates substantial variability both between surgeons and between rounds for individual surgeons when planning RTSA. Although average differences between plans were relatively small, there were large differences in specific cases suggesting little consensus on optimal planning parameters and opportunities to establish guidelines based on glenoid pathoanatomy. The correlation of preoperative planning with clinical outcomes will help to establish such guidelines.

Reverse Shoulder Arthroplasty in Patients with Rheumatoid Arthritis: Early Outcomes, Pitfalls, and Challenges

Objective

To evaluate the early outcomes and risk factors of reverse shoulder arthroplasty (RSA) in patients with rheumatoid arthritis (RA).

Methods

A retrospective study was performed on RA patients who had undergone RSA between January 2016 and January 2018. Preoperative glenohumeral joint damage was evaluated according to two radiographic classification systems. The severity of joint damage was estimated using Larsen's method, while the Levigne‐Franceschi method was used to assess the type of destruction. Further, we recorded intra‐ and postoperative complications. Visual Analogue Scale (VAS) was used to assess the degree of shoulder pain while shoulder function was evaluated with the American Shoulder and Elbow Surgeons (ASES) Shoulder Score. In addition, patients' subjective outcome and range of shoulder motion were recorded. Radiographs were taken and examined during the follow‐up period. Paired t‐test was used to determine the difference in measurement data between preoperative and the last follow‐up. VAS was analyzed using the Wilcoxon matched‐pairs signed‐rank test.

Results

A total of 14 patients with 14 shoulders were included. All the patients were female with an average age of 60.29 years (range, 49–71 years) at the time of surgery and an average RA disease duration of 24.57 years (range, 5–40 years). Seven of the 14 patients had a history of joint surgery related to RA. Meanwhile, 11 of the 14 shoulders showed glenoid bone defect, and eccentric reaming was performed intraoperatively to avoid base plate malposition. The mean follow‐up period for the 14 patients was 2.76 years (range, 2–4 years). The mean VAS decreased from a value of 5.71 ± 1.10 preoperatively to 1.36 ± 0.61 postoperatively (P < 0.001). On the contrary, the ASES score showed an increase from 33.93 ± 6.89 to 76.67 ± 5.23 (P < 0.001). An increase in active forward elevation, abduction, and external rotation with the arm in 90° of abduction from 85.71° ± 17.61°, 77.14° ± 19.43°, and 17.14° ± 10.97° to 126.43° ± 5.23°, 106.42° ± 11.72°, and 38.57° ± 14.57°, respectively, was observed (P < 0.001). Subjective outcome assessment showed that 13 of the 14 patients were very satisfied or satisfied with the operation, while one patient was uncertain due to co‐existing ipsilateral elbow lesion. Notably, one patient acquired a humeral periprosthetic fracture during the operation. In this study, no major complications such as periprosthetic joint infection and dislocation or implant loosening were observed. Further, no patients underwent revision for any reason at the end of the follow‐up.

Conclusions

RSA could achieve good early outcomes without high complication rates in patients with RA. Glenoid bone defects and adjacent joints involvement were common in this patient group, which might increase the risk of surgery and affect postoperative satisfaction.

In vivo volumetric and linear wear measurement of reverse shoulder arthroplasty at minimum 5-year follow-up

BACKGROUND

Reverse shoulder arthroplasty is quickly becoming the most frequently performed glenohumeral joint replacement. The purpose of this study was to evaluate the volumetric and linear wear rates of ultrahigh-molecular-weight polyethylene humeral liners in vivo at a minimum 5-year follow-up.

METHODS

Radiostereometric analysis was used to image 15 patients at terminal range of motion in forward flexion, abduction, external rotation, and internal rotation and with the arm at the side. The relative position and orientation of the glenosphere and polyethylene were identified for each arm position. The apparent intersection of the glenosphere into the polyethylene was recorded as wear. Mean volumetric and linear wear rates were recorded, and Pearson correlation coefficients were applied to the 36-mm liners to assess the relationship between the wear rate and term of service.

RESULTS

The mean reverse shoulder arthroplasty term of service at the time of imaging was 8 ± 1 years (range, 6-11 years). The mean volumetric and linear wear rates for the 36-mm liners (n = 13) were 42 ± 22 mm³/yr (r = 0.688, P = .009) and 0.11 ± 0.03 mm/yr (r = 0.767, P = .002), respectively. The mean volumetric and linear wear rates for the 42-mm liners (n = 2) were 114 ± 44 mm³/yr and 0.17 ± 0.01 mm/yr, respectively. No single arm position was able to capture all recorded wear individually.

CONCLUSION

This study showed volumetric and linear wear rates of approximately 40 mm³/yr and 0.1 mm/yr, respectively, for the 36-mm polyethylene liners. The 42-mm liners showed higher wear rates, although a greater number of subjects is required for conclusive results. In vivo wear of reverse total shoulder arthroplasty is multidirectional and perceptible.

Patient-reported outcomes of reverse total shoulder arthroplasty: a comparative risk factor analysis of improved versus unimproved cases

Background

The purpose of this study was to compare characteristics of patients who reported to be subjectively unimproved vs. improved after reverse total shoulder arthroplasty.

Methods

Data were derived from a prospective registry of patients who underwent reverse total shoulder arthroplasty with a minimum 2-year follow-up. Patients were asked to rate their subjective satisfaction and then divided into those who were unchanged or worse (unimproved group [UG]) vs. better or much better (improved group [IG]). The groups were compared for differences in demographic characteristics, preoperative factors, functional outcomes, and complications.

Results

There were 1425 patients in the IG and 134 patients in the UG. Patients in the IG were more likely to have a diagnosis of osteoarthritis. Patients in the UG were more likely to have coronary artery disease and diabetes and to have undergone prior surgery. No differences in implant configuration were found between groups. Preoperative measures for patients in the UG were worse for pain and function but not for range of motion. The outcomes in patients in the UG were worse for all postoperative measures, as well as for preoperative-to-postoperative improvement. Of the patients in the UG, 48% continued to have moderate to severe pain postoperatively. The complication rate was significantly higher in the UG.

Discussion

Up to 8.5% of patients rate themselves as unimproved after surgery. These patients are more likely to have certain comorbidities and to have undergone prior surgery. Although outcomes were significantly worse for all measures in the UG, improvement occurred in all measures despite patients subjectively being worse or unchanged. Residual pain and difficulty sleeping play a substantial role in subjective assessment of overall outcome.

Glenoid loosening and migration in reverse shoulder arthroplasty

Aims

The aim of this study was to report the outcomes of different treatment options for glenoid loosening following reverse shoulder arthroplasty (RSA) at a minimum follow-up of two years.

Patients and Methods

We retrospectively studied the records of 79 patients (19 men, 60 women; 84 shoulders) aged 70.4 years (21 to 87) treated for aseptic loosening of the glenosphere following RSA. Clinical evaluation included pre- and post-treatment active anterior elevation (AAE), external rotation, and Constant score.

Results

From the original cohort, 29 shoulders (35%) were treated conservatively, 27 shoulders (32%) were revised by revision of the glenosphere, and 28 shoulders (33%) were converted to hemiarthroplasty. At last follow-up, conservative treatment and glenoid revision significantly improved AAE, total Constant score, and pain, while hemiarthroplasty did not improve range of movement or clinical scores. Multivariable analysis confirmed that conservative treatment and glenoid revision achieved similar improvements in pain (glenoid revision vs conservative, beta 0.44; p = 0.834) but that outcomes were significantly worse following hemiarthroplasty (beta -5.00; p = 0.029).

Conclusion

When possible, glenoid loosening after RSA should first be treated conservatively, then by glenosphere revision if necessary, and last by salvage hemiarthroplasty Cite this article: Bone Joint J 2019;101-B:461–469.

Unsupervised and real-time spike sorting chip for neural signal processing in hippocampal prosthesis

BACKGROUND

Damage to the hippocampus will result in the loss of ability to form new long-term memories and cognitive disorders. At present, there is no effective medical treatment for this issue. Hippocampal cognitive prosthesis is proposed to replace damaged regions of the hippocampus to mimic the function of original biological tissue. This prosthesis requires a spike sorter to detect and classify spikes in the recorded neural signal.

NEW METHOD

A 16-channel spike sorting processor is presented in this paper, where all channels are considered as independent. An automatic threshold estimation method suitable for hardware implementation is proposed for the Osort clustering algorithm. A new distance metric is also introduced to facilitate clustering. Bayes optimal template matching classification algorithm is optimized to reduce computational complexity by introducing a preselection mechanism.

RESULTS

The chip was fabricated in 40-nm CMOS process with a core area of 0.0175 mm²/ch and power consumption of 19.0 μW/ch. Synthetic and realistic test data are used to evaluate the chip. The test result shows that it has high performance on both data.

COMPARISON WITH EXISTING METHOD(S)

Compared with the other three spike sorting processors, the proposed chip achieves the highest detection and classification accuracy. It also has the ability to deal with partially overlapping spikes, which is not reported in the other work.

CONCLUSIONS

We have developed a 16-channel spike sorting chip used in hippocampal prosthesis, which provides unsupervised clustering and real-time detection and classification. It also has the ability to deal with partially overlapping spikes.

Reverse total shoulder arthroplasty using helical blade to optimize glenoid fixation and bone preservation: preliminary results in thirty five patients with minimum two year follow-up

PURPOSE

Glenoid loosening is a common cause of reverse total shoulder arthroplasty (RTSA) failure, and grafting of the glenoid is often required for revision due to bone loss due to the central peg in most glenoid baseplates. Helical blades have been used in the hip to optimize bone fixation in proximal femoral fracture. This study presents the initial results of specifically designed helical blade in the shoulder to optimize glenoid bone fixation and preservation as part of RTSA.

METHODS

Thirty-five patients underwent RTSA with glenoid helical blade fixation. An uncemented glenoid baseplate was used with a central helical blade partially coated with hydroxyapatite and two or three screws. Outcome analysis was performed pre-operatively and at two years.

RESULTS

All patients were satisfied with the results and significant improvement was observed in functional outcome scores between baseline and final follow-up. There was a single intra-operative undisplaced glenoid fracture which did not compromise the baseplate fixation. There was no radiographic evidence of loosening or radiolucencies around the helical blade.

CONCLUSIONS

The helical blade provides a satisfactory primary fixation. Because of its length (21 mm), care should be taken in cases of pre-existing bone loss or sclerotic bone to avoid glenoid fracture or anterior cortical perforation. Helical blade has the potential to facilitate glenoid implant revision by preserving the glenoid bone stock.

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.

Reverse Shoulder Arthroplasty in Patients with Rheumatoid Arthritis: A Systematic Review

Background

There are limited data available regarding the results of reverse shoulder arthroplasty (RSA) in patients with rheumatoid arthritis (RA). We performed a systematic review of the literature to investigate the radiological and clinical outcomes after RSA in patients with RA.

Methods

A literature search for publications between 1987 and 2014 was conducted by 2 independent reviewers using PubMed, Scopus, Embase, and Cochrane Central Register of Controlled Trials. Articles were retrieved by an electronic search using keywords and their combinations. Studies that met inclusion criteria were assessed for pertinent data.

Results

Seven studies including 123 shoulders met the inclusion criteria. The mean age of the patients was 67.9 years and the mean follow-up period was 46.6 months. The mean Constant score and American Shoulder and Elbow Surgeons (ASES) score increased from 18.6 and 27.5 preoperatively to 58.6 and 73.7, respectively, at the final follow-up evaluation. The mean active forward flexion, abduction, and external rotation increased from 57.2°, 50.4°, and 11.4° to 127.1°, 116.7°, and 26.4°, respectively. The incidence of scapular notching was 33.7%. Twenty-seven (22.0%) of 123 shoulders had one or more complications, 12 of which (44.4%) had intraoperative or postoperative fractures. Nine shoulders (7.3%) had one or more revision surgeries.

Conclusions

RSA in RA showed similar short- to mid-term results without higher complication rates as compared to RSA in cuff tear arthropathy. Although RSA can be considered a reliable treatment option in patients with RA, further large-scale studies are required to determine the long-term survival of the implant.