Anatomic stemless shoulder arthroplasty and related outcomes: a systematic review

Does the proximal humeral bone quality influence alignment after reverse total shoulder arthroplasty with short humeral stems?

PURPOSE

When compared to standard-length humeral stem in reverse total shoulder arthroplasty (RTSA), short humeral stems in RTSA require good proximal humeral metaphyseal bone quality to gain proper and secure fixation during prosthetic implantation. Shorter humeral stems potentially carry more risk of misalignment than standard or long humeral stems. The hypothesis was that misalignment of the short humeral stems is influenced by regional bone quality.

METHODS

RTSA with a short curved humeral stem with neck-shaft angle (NSA) default of 132.5° was reviewed. The study group included 35 cases at a mean age of 75.97 (± 6.23) years. Deltoid-tuberosity index (DTI) was measured to evaluate proximal humeral bone quality. The deltoid tuberosity index was measured at immediately above position of the upper end of the deltoid tuberosity. Stem alignment was given by the angle measured in degrees between the intramedullary humeral shaft axis and the axis of the humeral implant stem.

RESULTS

The patient's mean DTI was 1.37 ± 0.16 (median, 1.32; range, 1.12-1.80). 22 patients had poor bone quality (DTI < 1.4), compared to 13 patients with acceptable bone quality (DTI > 1.4). After RTSA, ten humeral components (29%) were neutrally aligned, whereas 25 humeral components (71%) were misaligned. There was no correlation between misalignment and DTI (r = 0.117; p = 0.504). But there was a strong correlation between misalignment and the patient's own NSA (r = - 0.47; p = 0.004). The postoperative stem position and stem misalignment are not associated with functional outcomes (p > 0.05).

CONCLUSION

The misalignment of the short curved humeral stem frequently occurs. Poor reginal humeral bone quality does not influence misalignment after RTSA with a short humeral stem. Postoperative stem alignment is associated with the patient's preoperative NSA and method of neck cut. The misalignment does not affect functional outcomes for midterm follow-up. Further long-term follow-up studies are needed to confirm its clinical relevance.

Non-operative management of humeral periprosthetic fracture after stemless shoulder arthroplasty

PURPOSE

Periprosthetic fractures around a stemless implant often involve lesser and greater tuberosities with a well-fixed implant in the metaphysis. This exposes the surgeon to unique questions and challenges as no surgical option (open reduction and internal fixation or revision to a stem) appears satisfactory to address them. Purpose of this study was to evaluate the clinical outcomes after non-operative management of periprosthetic fractures after stemless shoulder arthroplasty.

METHODS

A retrospective multicenter study was conducted to identify all patients who had sustained non-operative management of a periprosthetic fracture after a stemless shoulder. Exclusion criteria were as follows: (1) intraoperative fractures and (2) implant loosening. Primary outcomes included mean Constant score and mean active range of motion. Secondary outcomes were VAS, radiological analysis, and complications.

RESULTS

Nine patients were included. One was excluded due to the loss of follow-up at three months. Mean age was 79 years. At the last follow-up, no significant difference was observed between the Constant score, VAS, or the range of motion before fracture and at the last follow-up. Fracture healing did not result in any change in angulation in the frontal plane in seven cases and was responsible for a varus malunion in two cases of anatomic arthroplasty. No change in lateralization or distalization was reported. No cases of implant loosening after fracture have been observed.

CONCLUSIONS

Conservative management seems to be appropriate in cases of minimally displaced fractures without implant loosening.

Anatomic glenohumeral arthroplasty: State of the art

Anatomical total shoulder arthroplasty in its modern form where it reproduces the normal shoulder has been utilized clinically for more than half a century. As the technology and the designs have changed to recreate the humeral and glenoid sides of the joint, the sophistication of design has resulted in the growing number of cases annually worldwide. This increase is due in part to the increasing number of indications that the prosthesis can treat with successful results. On the humeral side, there have been design changes to better reflect the proximal humeral anatomy, and humeral stems are increasingly placed safely without cement. Platform systems which allow conversion of a failed arthroplasty to a reverse configuration without stem extraction is another design change. Similarly, there has been increasing utilization of short stem and stemless humeral components. Extensive experience with shorter stem and stemless devices, however, has yet to demonstrate the purported advantages of these devices, as recent studies have demonstrated equivalent blood loss, fracture rates, operative times, and outcome scores. Easier revision with these shorter stems remains to be definitively established, with only one study comparing the ease of revision between stem types. On the glenoid side, hybrid cementless glenoids, inlay glenoids, cementless all-polyethylene glenoids, and augmented glenoids have all been investigated; however, the indications for these devices remain unclear. Lastly, innovative surgical approaches to implanting shoulder arthroplasty and the use of patient specific guides and computerized planning, while interesting concepts, still await validation before they are utilized on a widespread basis. While reverse shoulder arthroplasty has been increasingly used to reconstruct the arthritic shoulder, anatomic glenohumeral replacement maintains a significant role in the armamentarium of the shoulder surgeon.

Outcomes and survivorship of anatomic total shoulder arthroplasty: current concepts

Total shoulder arthroplasty (TSA) has been the gold standard of care for end-stage glenohumeral arthritis. Outcomes are varied and have been affected by both patient and implant characteristics. Patient factors, such as age, preoperative diagnosis, and preoperative glenoid morphology, can affect the outcomes after TSA. Similarly, the different glenoid and humeral component designs significantly affect the survivorship of TSA. Significant evolution has occurred in the design of the glenoid component with the aim of decreasing the glenoid-sided causes of failure in TSA. On the other hand, focus on the humeral component has been increasing as well, with a trend towards using shorter humeral stems. This article aims to look at the outcomes of TSA as affected by the various patient characteristics and design options for the glenoid and the humeral components. This review also aims to compare survivorship data from global literature and the Australian joint replacement registry and to provide insights into the implant combination that may provide the best patient outcome.

A survey and biomechanical analysis of the feasibility of the thumb test for determining the cancellous bone quality for stemless shoulder prosthesis

BACKGROUND

The effect of the thumb test for assessing the cancellous bone quality at the resection plane of the proximal humerus on determining the application of a stemless shoulder prosthesis remains unclear. This study was conducted to survey the current utilization of the thumb test among surgeons and to investigate biomechanical features of the thumb test.

METHOD

A survey among shoulder surgeons who had experience with stemless prostheses was conducted to investigate the current utilization of preoperative assessments and intraoperative thumb test when applying stemless prosthesis. Biomechanical experiments for the thumb test using artificial bone models were performed to assess the compression force, contact pressure and area. According to the preliminary survey, three compression techniques were assessed: compression perpendicular to the surface with thumb pad (P-pad technique) or tip of the thumb (P-tip technique), or compression in the vertical direction simulating compression along the longitudinal axis of the humeral shaft with tip-pad of the thumb (H-axis technique). The contact area was separated into three subregions (proximal, middle and distal) to assess the distribution of contact pressure.

RESULTS

Among 38 surgeons, 66% utilized the thumb test intraoperatively. The P-pad technique was more frequently applied than the P-tip or H-axis techniques (80%, 4% and 16%, respectively). Although with wide variation among the examiners, biomechanical assessments revealed the P-pad technique showed larger contact area and less compression force than the P-tip technique. The P-pad technique provided no significant localized differences in the mean contact pressure on the compressed plane, whereas the P-tip and H-axis techniques showed significant differences among subregions.

CONCLUSION

This survey demonstrated relatively frequent application of the thumb test on applying the stemless shoulder prosthesis. Biomechanical assessment revealed the thumb test can hinder objective reproducibility among examiners; therefore, further investigations to identify feasible assessments of the bone quality is required.

Osteoporosis in the Setting of Shoulder Arthroplasty: A Narrative Review

Patients who undergo shoulder surgery are frequently affected by osteoporosis and osteopenia, and the prevalence of this association is expected to increase due to the growing number of elderly individuals undergoing these procedures. It may be advisable to conduct a preoperative DXA scan for orthopedic surgical candidates at high risk, to detect those who could benefit from early intervention and avoid any related adverse events. Some of these complications include periprosthetic fractures, infection, subsequent fragility fractures, and have an all-cause revision arthroplasty at 2 years post-op. Some studies analyzed the beneficence of antiresorptive medications pre-operatively but the latter did not show favorable outcomes. Surgical management may include cementing components of the prosthesis as well as modifying the diameter of the shoulder stem. Nevertheless, more studies are needed to evaluate the efficacy of any intervention, whether medical or surgical, to avoid any shoulder arthroplasty related-complication that may be precipitated by the reduced bone mineral density.

Short-term radiographic analysis of a stemless humeral component for anatomic total shoulder arthroplasty

Background

Standard stemmed humeral implants have traditionally been utilized for total shoulder arthroplasty (TSA) with a recent trend to implant smaller stems including short and stemless humeral designs. However, the rate of stress shielding after stemless TSA has not been primarily studied. Therefore, the objective of this study is to report the short-term survivorship and radiographic analysis of a stemless humeral implant.

Methods

A retrospective cohort review of a prospectively collected, multicenter database for patients undergoing total shoulder arthroplasty with a stemless humeral design (Equinoxe Stemless; Exactech, Inc., Gainesville, FL, USA) with a minimum of 2 years clinical and radiographic follow-up was performed. The primary outcomes were to report the location and rate of stress shielding from a radiographic analysis of the humeral stem. Additionally, the revision rate of the humeral stem is reported. The secondary outcomes included ASES scores, visual analog scale (VAS) pain scores, and range of motion (ROM). Radiographs (anterior-posterior/Grashey and axillary) were reviewed blindly by two fellowship trained shoulder surgeons. Radiographic analysis included stress shielding (partial or complete cortical resorption) and subsidence or shift in component position.

Results

Fifty four patients were included in this study with an average follow-up of 27 months (range 24-32 months). The average age of this cohort was 65 years (range 57-73 years) with 23 patients (43%) being female. Stress shielding was observed in 4 patients (7%) with the medial calcar being the most common location of stress shielding. Three of the 4 patients (75%) had evidence of partial resorption while 1 patient (25%) had evidence of complete resorption. No humeral component shift or subsidence was observed. There were no revisions due to humeral component complications. There was 1 revision surgery for aseptic glenoid loosening. A significant improvement for all clinical outcome measures was seen including with respect to VAS pain, which improved from 6.2 to 1.8 (P < .05), ASES, which improved from 38.2 to 81.8 (P < .05), and ROM which forward flexion improved from 120 degrees to 153 degrees (P < .05) and external rotation improved from 29 degrees to 49 degrees (P < .05).

Discussion

This ongoing study demonstrates a low rate of stress shielding for a stemless design humeral implant at short-term follow-up without any revision surgery due to humeral component complications. Longer term radiographic and clinical analysis with this cohort will be needed to confirm these findings and theoretical benefits for future revision surgeries.

Lesser Tuberosity Osteotomy Healing in Stemmed and Stemless Anatomic Shoulder Arthroplasty Is Higher with a Tensionable Construct and Affected by Body Mass Index and Tobacco Use

BACKGROUND

This study compared the healing rates of lesser tuberosity osteotomy (LTO) for anatomic total shoulder arthroplasty (TSA), repaired with either standard knot tying or a tensionable construct. Second, we evaluated LTO healing in stemmed and stemless prostheses and identified the patient characteristics associated with healing.

METHODS

An analysis of consecutive primary TSAs approached with an LTO performed by a single surgeon between 2016 and 2020 was conducted. In the first two years of the study period, the LTOs were repaired with four #2 polyblend sutures passed through drill tunnels and around a short press-fit stem, followed by manual knot tying. Subsequently, a tensionable construct with suture tapes (TCB) was universally adopted. The radiographic appearance of the LTO was evaluated at a minimum of six months postoperatively.

RESULTS

A total of 340 patients met the study criteria, including 168 with manual knot tying, 84 TCB repairs with a stemmed implant, and 88 TCB repairs with a stemless implant. There was no difference in the baseline demographics between the groups. The LTO healing rate of the manual knot tying group (85%) was lower than that of the stemmed (95%) and stemless (98%) TCB groups (p < 0.001). When directly comparing the LTO healing between the stemmed and stemless TCB groups, the differences were not significant (p = 0.44). Across all constructs, the body mass index (BMI) was higher in the displaced nonunion group (p = 0.04), with a failure rate of 9.4% for a BMI between 30 and 40, 12.5% for a BMI between 40 and 50, and 28.6% for a BMI > 50. The rate of tobacco use was higher in the displaced nonunion group (p = 0.037).

CONCLUSION

A tensionable construct improves LTO healing compared to manual knot tying, irrespective of the implant type. In addition to the surgical technique, the patient factors that influence tuberosity healing include a greater BMI and tobacco use.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Outcomes Between Stemmed and Stemless Total Shoulder Arthroplasty: A Systematic Review and Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Both stemmed and stemless designs for total shoulder arthroplasty (TSA) have demonstrated efficacious outcomes for the surgical treatment of primary glenohumeral joint osteoarthritis. The purpose of this systematic review and meta-analysis was to compare the clinical outcomes of stemmed versus stemless TSA in randomized controlled trials. We hypothesized that there would be no differences in Constant Score (CS), range of motion, or adverse events, such as periprosthetic fracture and/or revision surgery.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, a systematic review of the literature was done using MEDLINE, SPORTDiscus, Cumulative Index to Nursing and Allied Health Literature, Cochrane Central Registry of Controlled Trials, Embase, and Web of Science databases. Outcomes of interest included CS, range of motion, and adverse events (periprosthetic fracture and revision). Summary effect estimates of the mean difference between stemmed and stemless TSA for each outcome were estimated in random effects models.

RESULTS

The search yielded 301 articles with 4 appropriate for qualitative analysis, including the results of 229 stemmed and 358 stemless TSAs. No significant difference was observed in postoperative CS (P = 0.36), forward flexion (P = 0.93), abduction (P = 0.30), or external rotation (P = 0.34) between stemmed and stemless TSA. No significant difference was observed in change in CS (P = 0.27), forward flexion (P = 0.25), or external rotation (P = 0.74). A change in abduction was significantly different between stemmed and stemless TSA (standardized mean difference = -0.64; 95% confidence interval, -1.20 to -0.08) in favor of stemmed TSA (P = 0.02), attributed to preoperative differences. No significant difference was observed in periprosthetic fractures (P = 0.07) or revision (P = 0.90).

CONCLUSION

TSA with stemless versus stemmed humeral components was not associated with notable differences in functional and clinical outcomes. No difference was observed between stemmed and stemless designs in postoperative forward flexion, abduction, or external rotation. Similarly, there was no difference in change in forward flexion or external rotation. A markedly greater improvement in abduction was observed with stemmed TSA, likely due to the lower preoperative motion in the stemmed cohort in one of the studies. No differences were observed between stemmed and stemless designs in the rate of humeral fracture or risk of revision.

LEVEL OF EVIDENCE

Level II; systematic review and meta-analysis of prospective randomized controlled trials.

Stemless anatomic total shoulder arthroplasty: surgical technique and review of the literature

Stemless anatomic total shoulder arthroplasty (aTSA) is a promising option for the treatment of degenerative disease in patients. This novel technique avoids the stem-related complications associated with the traditional stemmed aTSA. Stemless aTSA offers additional benefits such as decreased operative time, preservation of bone stock, improved radiographic outcomes, and easier revision. Moreover, loading of the metaphyseal region rather than the diaphysial region with traditional stemmed implants can decrease stress shielding. When compared to stemmed-implants, stemless aTSA has demonstrated similar outcomes and complication rates. The purpose of this article is to analyze published outcomes and complications following the utilization of stemless aTSA. Additionally, key aspects of the surgical technique that may promote optimal results in stemless aTSA implantation are presented.

Short-term results of a new anatomic stemless shoulder arthroplasty - A prospective multicentre study

Background

Anatomic total shoulder arthroplasty (TSA) has been continuously developed and current designs include stemless or canal-sparing humeral components. In the literature stemless and canal sparing TSA showed good clinical and radiographic results, which were comparable to stemmed TSA.

Objective

The aim of this study was to determine the short-term clinical and radiological outcomes of a new stemless TSA design.

Methods

A prospective multicentre study including 154 total shoulder arthroplasty patients with a follow up of 12 months was performed. At the time of follow up 129 patients were available for review. The adjusted Constant Murley score,¹ Oxford Shoulder Score, EQ-5D-5L score and radiographs were examined preoperatively, 3 and 12 months after the implantation of the new stemless TSA implant GLOBAL ICON™ (DePuy Synthes, Warsaw, IN, USA). Complications were documented.

Results

Implant Kaplan-Meier survivorship was 98.7% at 12 months. From baseline to 12 months follow-up, all scores showed a progressive significant mean improvement. The mean adjusted Constant score increased from 42.3 to 96.1 points (p<0.001). The Oxford Shoulder Score showed an increase of 21.6 points (p<0.001). The postoperative radiographs showed no continuous radiolucent lines, subsidence, aseptic loosening or progressive radiolucency, but one osteolytic lesion was observed. Only 2 prostheses were revised.

Conclusion

The new GLOBAL ICON stemless TSA showed good clinical and radiographic results at short-term follow up which were comparable to early results of other stemless TSA. Further studies with longer follow up are needed in the future.

Stemless Hemiarthroplasty and Anterior Capsular Reconstruction in the Setting of a Residual Humeral Limb: A Case Report

CASE

We present a 58-year-old left hand-dominant woman with right glenohumeral osteoarthritis and anterior instability in the setting of a congenital residual limb at the level of the mid-humerus. She had persistent pain and dysfunction despite trying conservative treatments and elected for a stemless or "canal-sparing" hemiarthroplasty with anterior capsular reconstruction. At the 2-year follow-up, there was significant improvement in her pain, motion, and function without signs of radiographic loosening.

CONCLUSION

A stemless humeral implant is a versatile component that can be used in the face of humeral dysplasia, such as this patient with a congenital residual limb.

Surgical time and outcomes of stemmed versus stemless total shoulder arthroplasty

BACKGROUND

Stemless total shoulder arthroplasty (TSA) was approved for use in the United States in 2015, and there remains a paucity of data on its performance in this market. Decreased operative time without compromise of clinical outcomes is a theoretical advantage of stemless TSA, but no studies have evaluated this in a comparative study to date. Herein, the operative times and clinical outcomes of stemless vs. conventional stemmed TSA are investigated.

METHODS

This is a retrospective cohort study, evaluating all consecutive TSAs performed by a single surgeon between 2015 and 2018. Data were collected from 59 patients who underwent TSA with conventional, stemmed humeral implants and 115 patients in whom a stemless humeral implant was used. Operative times and demographic data were collected retrospectively from the anesthesia record, and prospectively collected patient-reported outcome measures were collected from the Surgical Outcomes System database. For patient-reported outcome measure, visual analog scale, American Shoulder and Elbow Surgeons, and Single Assessment Numerical Evaluation scores were recorded serially until a minimum 2-year follow-up.

RESULTS

The average operative time was 24 minutes less in the stemless cohort compared with the stemmed cohort (104 minutes vs. 128 minutes, P < .001). Cost analysis showed a decreased personnel cost of 15.9% that correlates to a 3.1% overall reduction in operating room-associated cost. Patient-reported outcome scores significantly improved postoperatively in both cohorts across all time points. There was no difference found in visual analog scale, American Shoulder and Elbow Surgeons, and Single Assessment Numerical Evaluation scores between the cohorts at the 2-year follow-up.

CONCLUSIONS

Stemless TSA significantly reduces operative time with equivalent functional outcomes at a minimum 2-year follow-up.

Stemless reverse total shoulder arthroplasty: a systematic review

BACKGROUND

The use of reverse total shoulder arthroplasty and stemless anatomic total shoulder replacement has been increasing in the United States every year. Stemless humeral components in reverse total shoulder arthroplasty are only approved for clinical trials in the United States with an investigational device exception with limited data.

METHODS

A systematic review on stemless reverse total shoulder arthroplasty was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. A search was conducted on November 25, 2020, using the MEDLINE/PubMed, Cochrane, and Embase databases. All articles were reviewed by 2 independent evaluators, with any conflicts or issues resolved by consensus or a final decision by the senior author. The primary outcomes extracted were complications, radiographic results, and outcome scores.

RESULTS

We evaluated 10 studies that used either the Total Evolutive Shoulder System (TESS) or Verso implant. There were 430 total patients and 437 total procedures; 266 patients in the TESS group underwent a total of 272 procedures, and 164 patients in the Verso group underwent a total of 165 procedures. The mean age at the time of surgery was 73.8 years (range, 38-93 years). The mean follow-up period ranged from 6.4 to 101.6 months per study. There was an overall trend of improved clinical outcome scores, a 0.2% humeral component loosening rate, and an 11.2% complication rate.

CONCLUSIONS

This review shows that the clinical and functional outcomes following stemless or metaphyseal reverse total shoulder arthroplasty are quite promising, especially with the low rate of humeral-sided complications. There continues to be a need for additional long-term studies and randomized clinical trials.

Determining the ideal osteotomy for stemless total shoulder replacement: a cadaveric study

HYPOTHESIS

We sought to determine the angle of osteotomy that produces a circular humeral cut surface.

METHODS

A total of 49 cadaveric shoulders, from 25 cadavers, underwent sequential humeral head osteotomy from 180° (vertical, in line with the humeral diaphyseal shaft), in 10° increments, until the rotator cuff insertion was encountered. At each stage, the anteroposterior (AP) and superoinferior (SI) distances were recorded. The data were analyzed for normality and then assessed to determine the optimum cut angle.

RESULTS

The AP/SI ratio is an indication of roundness. Plotting values of 1 - AP/SI (ie, error) vs. cut angle allowed us to plot the likelihood of producing a circular cut surface using a third-order curve that created the best fit to the data set (R² = 0.99). The results from this study suggest that the optimum osteotomy angle that produces a circular cut surface is 23° from the vertical. The cohort data illustrated that at this angle, the average roundness error was 1% with a 95% confidence limit of <1%. There was no significant difference (P > .05) between sexes.

CONCLUSION

The humeral head shape changes from oval to circular and then to an oval cut surface as the osteotomy angle increases from the vertical toward the horizontal. The range of angles within which the cut surface is circular, within a 10% error margin, is 18°-27° from the vertical, which is much less than the traditional osteotomy angle of 45°.

Mid-term results of Eclipse total shoulder arthroplasty

AIMS

The use and variety of stemless humeral components in anatomical total shoulder arthroplasty (TSA) have proliferated since their advent in 2004. Early outcomes are reassuring but independent mid-term results are scarce. This independent study reports a consecutive series of 143 Eclipse stemless shoulder prostheses with a minimum five-year (5 to 10) follow-up.

METHODS

Outcomes of 143 procedures undertaken for all indications in 131 patients were reviewed, with subset analysis of those for osteoarthritis (OA) (n = 99). The primary outcome was the Oxford Shoulder Score (OSS) at a minimum of five years. Secondary outcomes were ranges of motion and radiological analysis of humeral radiolucency, rotator cuff failure, and glenoid loosening.

RESULTS

Mean OSS at mean follow-up of 6.67 years (5.0 to 10.74) was 40.12 (9 to 48), with no statistically significant difference between those implanted for a non-OA indication and those for OA (p = 0.056) or time-dependent deterioration between two years and five years (p = 0.206). Ranges of motion significantly improved compared with preoperative findings and were maintained between two and five years with a mean external rotation of 38° (SD 18.1, 0 to 100) and forward elevation of 152° (SD 29.9, 90 to 180). Of those components with radiographs suitable for analysis (n = 83), 23 (28%) were found to have a least one humeral radiolucent line, which were predominantly incomplete, less than 2 mm, and in a single anatomical zone. No humeral components were loose. A radiolucent line was present around 22 (15%) of glenoid components, and 15 (10%) of components had failed. Rotator cuff failure was found in 21 (15%) components. The mean time to either glenoid or rotator cuff failure was greater than three years following implantation. Survivorship was 96.4% (95% CI 91.6 to 98.5, number at risk 128) at five years, and 94.3% (95% CI 88.2 to 97.3, number at risk 76) at seven years, both of which compare favourably with best results taken from available registries.

CONCLUSION

Functional and radiological outcomes of the Eclipse stemless TSA are excellent, with no loose humeral components at minimum five-year follow-up. The presence of radiolucent lines is of interest and requires long-term observation but does not impact on the clinical results. Of the eight revisions required, this was predominantly for glenoid and rotator cuff failure. Cite this article: Bone Joint J 2022;104-B(1):83-90.

Anatomic and Reverse Stemless Shoulder Arthroplasty: Functional and Radiological Evaluation

Background

Stemless shoulder arthroplasty was developed to restore the glenohumeral centre of rotation without violation of the humeral shaft. It allows the preservation of humeral bone stock. Complications related to stem malalignment and periprosthetic fractures can be avoided.

Patient and methods

This is a prospective observational study that reports outcomes of 46 patients who received stemless shoulder arthroplasty “Comprehensive Nano implant ®.” The series includes Group (A): 30 anatomic and one hemiarthroplasty. Group (B): 15 reverse stemless replacement. Functional outcomes were assessed by visual analog score (VAS), satisfaction, range motion, Constant score, and American Shoulder and Elbow Score (ASES).

Results

The mean follow-up was 40.4  ±  12 months (range, 24 months to 60 months). Group (A): VAS and satisfaction improved by 5.3 and 67.5 points respectively. Constant score significantly improved from 28.5  ±  14.5 to 62.5  ±  23 P = <0.001. The radiological assessment showed the mean centre of rotation (COR) deviation was 2.8  ±  1.9 mm. 27% of patients have COR discrepancy of more than 4 mm. In Group (B), patients reported a significant improvement in VAS, Satisfaction, and ASES P  =  0.002, 0.002, and 0.003, respectively.

Complications include shoulder pain with progressive loss of movements, aseptic loosening early subscapularis rupture, glenohumeral dislocations, and humeral component migration.

Conclusion

Anatomic Stemless total shoulder arthroplasty offers acceptable results and improvement of overall functional outcomes.

Extra-short humeral heads reduce glenohumeral joint overstuffing compared with short heads in anatomic total shoulder arthroplasty

Background

Rotator cuff tears and glenoid loosening remain the two most common causes for revision after anatomic total shoulder arthroplasty. Oversizing of the humeral head leads to increased contact force across the glenohumeral joint and is hypothesized to contribute to clinical and radiographic failure. The purpose of this study is to compare the rate of radiographic overstuffing between standard short humeral heads and newer extra-short heads with decreased lateral offset.

Methods

Fifty-five consecutive anatomic total shoulder arthroplasties performed using extra-short humeral heads were retrospectively reviewed and compared with age- and sex-matched controls receiving standard short heads. A total of 110 postoperative radiographs were analyzed using the Iannotti's perfect circle method to compare the prosthesis' center of rotation (COR) with the native humeral head COR. A difference in the COR of >3.0 mm was considered malpositioned. Malpositioning medially was considered overstuffed, and malpositioning laterally was considered understuffed. The direction of displacement of malpositioned prostheses was categorized using a quadrant system. Furthermore, we used a novel method to evaluate medial and superior overstuffing by measuring the displacement between the anatomic and prosthetic head positions along perpendicular axes.

Results

Using the Iannotti's perfect circle method, 56% of heads were malpositioned. Overstuffing occurred more frequently with short heads compared with extra-short heads (47% vs. 4%, P < .001). Conversely, understuffing occurred more frequently with extra-short heads (47% vs. 15%, P = .001). Malpositioned extra-short heads were most frequently placed in the inferomedial quadrant (93% vs. 24%, P < .001), whereas malpositioned short heads were most commonly placed in the superomedial quadrant (56% vs. 7%, P < .001). Our novel measurement method demonstrated that extra-short heads reduced medial overstuffing (2.8 ± 2.8 mm vs. 0.3 ± 2.0 mm, P < .001). Both extra-short and short heads had similar rates of superior malpositioning (1.6 ± 2.2 mm vs. 1.4 ± 1.5 mm, P = .683).

Conclusion

Routine use of extra-short humeral head sizes reduces the rate of medial glenohumeral joint overstuffing but not superior malpositioning. This is hypothesized to improve clinical outcomes, but future studies are needed to assess the relationship between improved humeral head fit and clinical outcomes.

Midterm clinical and radiologic survivorship of a stemless total shoulder arthroplasty

AIM

The aim of this study was to evaluate the clinical and radiologic outcomes of stemless total shoulder arthroplasty (TSA) in patients with glenohumeral arthritis.

PATIENTS AND METHODS

This is a retrospective case series of all patients who underwent a TSA with Affinis Short prosthesis during the period 2010-2017. Seventy-two TSAs were performed within our unit, in 62 patients (45 females and 17 males), with 10 patients having bilateral TSAs with this prosthesis. The mean follow-up was 3.9 years (2-8.7 years). Patients were evaluated clinically with the Oxford Shoulder Score, range of movement assessment, and a numerical patient satisfaction score. Follow-up radiographs were evaluated by 2 reviewers assessing for lucency and assigned a Lazarus grade.

RESULTS

Six patients were lost to follow-up prior to their 2-year review. At last follow-up, the mean forward elevation was 157° (80°-180°), abduction was 150° (60°-180°), and external rotation was 39° (20°-60°). The mode internal rotation was to the lumbar spine, with 95% of patients achieving internal rotation to L5 or higher. The mean Oxford Shoulder Score was 45 (18-48). The mean patient satisfaction score was 4.93/5. No humeral lucencies were observed. Sixty-four percent (n=47) of the glenoids were Lazarus grade 0, showing no evidence of radiolucency. The remaining patients were Lazarus grade 1-3, although none were progressive and all patients were asymptomatic. No patients were revised for aseptic loosening. Four patients underwent revision: 1 for infection, 1 for heterotrophic ossification and stiffness, and 2 for rotator cuff failure.

CONCLUSION

Midterm follow-up results indicate good clinical and radiologic survivorship for this stemless TSA. Our findings suggest good patient function and satisfaction, and no patients have required revision for aseptic loosening. Further follow-up is required to determine long-term survivorship.

Clinical and radiologic results after anatomic stemless shoulder prosthesis: a minimum 4-year follow-up

BACKGROUND

Since the introduction of stemless anatomic shoulder arthroplasty, few midterm functional and radiographic results have been published. This article presents results of the Arthrex Eclipse prosthesis with a mean follow-up of 70 months.

METHODS

We prospectively evaluated the outcome of 53 arthroplasties in 51 patients with a mean age of 65 years at the time of implantation with a minimum follow-up of 48 months. All patients were physically and radiologically examined, and the results documented by Constant-Murley and Disabilities of the Arm, Shoulder, and Hand (DASH) scores.

RESULTS

Significant improvements from preoperative to last follow-up were documented in the Constant-Murley score (53.8%-83.5%, P < .001) and active range of motion (abduction 84°-108°, flexion 98°-125°, and external rotation 19°-41°). There was no significant difference between total and hemiarthroplasty. The mean DASH score was 28.3 points (95% confidence interval 20.1-35.2). Lowering of bone mineral density was observed in anteroposterior radiographs at the humeral component in 24.5% and at the glenoid component in 33.3%. The rate of complications was 15.7%.

CONCLUSION

This study finds improvements in functional, radiographic, and subjective midterm results comparable to other accessible data for stemless and stemmed arthroplasty.

Stemless Total Shoulder: A Review of Biomechanical Fixation and Recent Results

Introduction: Anatomic total shoulder arthroplasty is the replacement of the humeral head and glenoid surfaces with the goal of replicating normal anatomy. It is commonly utilized for patients with osteoarthritis, rheumatoid arthritis, and osteonecrosis, who have decreased range of motion (ROM), persistent pain, and loss of strength. Total shoulder Arthroplasty (TSA) is the third most common joint replacement in the United States. The incidence of TSA has been increasing, some data suggest that by the year 2025, TSA incidence may rise to 439,206 operations per year. In recent years, stemless total shoulder implants have become available. Results: These implants preserve bone stock while decreasing complications such as osteolysis, stress shielding and periprosthetic fracture. Stemless implants improve anatomic reconstruction and biomechanical function of the shoulder joint. Conclusion: Increasing amounts of data suggest stemless TSA to be a safe and effective technology that will become more common in the coming year.

Stemless Total Shoulder Arthroplasty for a 4-Part Proximal Humerus Malunion and Post-traumatic Arthritis: A Case Report

CASE

We present a 62-year-old left-hand-dominant woman with history of renal failure, osteoporosis, and 4-part proximal humerus fracture malunion with subsequent post-traumatic arthritis of the left glenohumeral joint. After conservative treatments failed to relieve her symptoms, the patient underwent stemless total shoulder arthroplasty (TSA) because of concerns that her proximal humerus could not accommodate a stemmed implant. At 2 and a half-years postoperative, the patient demonstrated significant improvement of symptoms without signs of radiographic loosening.

CONCLUSION

In the setting of proximal humerus malunion with post-traumatic arthritis, clinical improvement without implant loosening can be achieved with stemless TSA, even in the setting of compromised bone quality.

Mid-term results of a stemless ceramic on polyethylene shoulder prosthesis - A prospective multicentre study

INTRODUCTION

Early reports of stemless shoulder arthroplasty have shown promising clinical and radiological outcomes. The purpose of this study was to report on the mid-term results of an implant that utilises a ceramic humeral head.

METHODS

A prospective, consecutive, multicentre study of stemless shoulder prosthesis with a minimum of four years of follow-up was conducted between August 2009 and May 2012. The adjusted Constant-Murley Score (CMS), revision rate and presence of radiolucent lines were recorded at intervals.

RESULTS

A total of 207 patients were eligible for study inclusion; 62.8% were female and mean age was 64.8 years (range 30-86). Mean follow-up was 70.7 months (range 48-100), 73% underwent TSA and 27% hemiarthroplasty. The mean CMS improvement was 42.6 (p < 0.0001) at 48 months. Radiolucencies were present in 2.7% of humeral zones and 14% of glenoid zones at 48-month follow-up. The revision rate was 6.3% with rotator cuff failure (2.9%) the most common indication.

CONCLUSIONS

Mid-term results demonstrate that the studied stemless implant with a ceramic humeral head had clinical and radiological outcomes that are comparable to other reported studies.

Stemless Total Shoulder Arthroplasty With Orthobiologic Augmentation

Total shoulder arthroplasty (TSA) has evolved over the years and is used for a variety of indications, with arthritis being the most common. Stemless TSA is a unique bone-preserving design that can eliminate rotational malalignment. Additionally, recent literature has found utility in the use of biological mesh and a platelet-rich plasma injection to improve healing. The purpose of this article is to outline the process of TSA using a stemless system and how to incorporate the use of amnion matrix and platelet-rich plasma into the surgical technique.

3D-Analysis of the Proximal Humeral Anatomy Before and After Stemless Shoulder Arthroplasty-A Prospective Case Series Study

BACKGROUND

Stemless shoulder arthroplasty (SSA) is used to anatomically reconstruct proximal humerus geometry and preserve proximal humerus bone stock. The current literature lacks 3D-analysis of pre- and postoperative proximal humeral anatomy after SSA. The aim of this study was to prospectively analyze the humeral head anatomy using a computer-assisted topography mapping technique after SSA in relation to the preoperative status and the contralateral (not affected) side.

METHODS

Twenty-nine patients (mean age: 63.5 ± 11.7 years) affected by primary shoulder osteoarthritis and treated with SSA were included. Preoperative and postoperative CT scans of the affected and contralateral sites were analyzed regarding joint geometry. Clinical outcome was assessed by Constant and Disabilities of the Arm, Shoulder and Hand (DASH) score shortly before and one year after surgery.

RESULTS

Clinical outcome improved significantly. No correlation between clinical outcome and the evaluated anatomical parameters was found. There was a significant decrease of the humeral head height (p < 0.01) and radius (p = 0.03) in the preoperative versus the postoperative joint geometry. The comparison to the contralateral site showed also a significant decrease of the humeral head height (p < 0.01). All other parameters showed no significant differences.

CONCLUSION

Proximal humeral anatomy can be almost anatomically reconstructed by SSA. Solely the humeral head height differs significantly to the preoperative as well as contralateral morphology.

Revision of a Stemless Anatomic Implant into a Stemless Reverse Implant

Introduction

Stemless anatomic implants are the growing standard for solving osteoarthritis of the shoulder. If there are secondary rotator cuff insufficiency and the need to revise the implant into a reverse total shoulder, there is usually the option to revise it into a stemmed implant with losing the benefits of stemless implants. There are only a few stemless reverse implants available on the market. Usually, they are recommended as primary implants, but not for revision surgery. Case Report. A 61-year-old male with an indwelling anatomic stemless TESS (Total Evolutive Shoulder System, Zimmer Biomet, Warsaw, USA) implant presented in our clinic with growing pain and loss of range of motion. The TESS was implanted in 2007 as a hemishoulder arthroplasty. The X-ray was showing a stable implanted corolla with clearly growing protrusion of the glenoid. Because of the clinical presentation and the ultrasound investigation that showed only remnants of the supraspinatus and infraspinatus left, we decided that it is necessary to revise the stable implant in a reverse total shoulder arthroplasty. As the TESS was not designed to be convertible, it was clear that it has to be explanted. Due to the young age of the patient, we proposed an “off-label” change to a stemless reverse implant, e.g., the LIMA SMR stemless reverse prosthesis. A revision was possible without much bone loss, so the stemless reverse implant could be used. The clinical and radiological 2-year follow-up showed a good result.

Conclusion

Stemless implants are well known for anatomic implants, rarely for reverse implants, and seldom used for revision into reverse stemless. This case report shows that it is possible to revise a stemless anatomic implant with a stemless reverse, as long as the rules for implantation are applicable.

Prevalence and Treatment of Osteoporosis Prior to Elective Shoulder Arthroplasty

Introduction:

The rate of preoperative osteoporosis in lower extremity arthroplasty is 33%. The prevalence of osteoporosis in shoulder arthroplasty patients is inadequately studied. The purpose of this study was to (1) determine the prevalence of osteoporosis in patients undergoing elective shoulder arthroplasty, (2) report the percentage of patients having dual-energy x-ray absorptiometry (DEXA) testing before surgery, and (3) determine the percentage of patients who have been prescribed osteoporosis medications within 6 months before or after surgery.

Methods:

This retrospective case series included all adults aged 50 years and older who underwent elective shoulder arthroplasty at a single tertiary care center over an 8-year period. National Osteoporosis Foundation (NOF) criteria for screening and treatment were applied.

Results:

Two hundred fifty-one patients met the inclusion criteria; 171 (68%) met the criteria for DEXA testing, but only 31 (12%) had this testing within 2 years preoperatively. Eighty patients (32%) met the NOF criteria for receipt of pharmacologic osteoporosis treatment, and 17/80 (21%) received a prescription for pharmacotherapy.

Discussion:

Two-thirds of elective shoulder arthroplasty patients meet the criteria to have bone mineral density measurement done, but less than 20% have this done. One in three elective shoulder arthroplasty patients meet the criteria to receive osteoporosis medications, but only 20% of these patients receive therapy.

Eclipse stemless shoulder prosthesis vs. Univers II shoulder prosthesis: a multicenter, prospective randomized controlled trial

BACKGROUND

Total shoulder arthroplasty is an accepted treatment for glenohumeral osteoarthritis. The Arthrex Eclipse shoulder prosthesis is a stemless, canal-sparing humeral prosthesis with bone ingrowth capacity on the trunnion, as well as through the fenestrated hollow screw, that provides both diaphyseal and metaphyseal load sharing and fixation.

METHODS

Between 2013 and 2018, 16 sites in the United States enrolled 327 patients (Eclipse in 237 and Arthrex Univers II in 90). All patients had glenohumeral arthritis refractory to nonsurgical care. Strict exclusion criteria were applied to avoid confounding factors such as severe patient comorbidities, arthritis not consistent with osteoarthritis, and medical or prior surgical treatments that may have affected outcomes. Patients were randomized to the Eclipse or Univers II group via block randomization.

RESULTS

In total, 149 Eclipse and 76 Univers II patients reached 2-year follow-up (139 Eclipse patients [93.3%] and 68 Univers II patients [89.5%] had complete data). The success rate using the Composite Clinical Success score was 95% in the Eclipse group vs. 89.7% in the Univers II group. No patient exhibited radiographic evidence of substantial humeral radiolucency, humeral migration, or subsidence at any point. Reoperations were performed in 7 patients (3.2%) in the Eclipse group and 3 (3.8%) in the Univers II group.

CONCLUSION

The Arthrex Eclipse shoulder prosthesis is a safe and effective humeral implant for patients with glenohumeral arthritis at 2-year follow-up, with no differences in outcomes compared with the Univers II shoulder prosthesis.

Primary stability analysis of stemless shoulder implants

Although the primary stability of joint implants is fundamental for successful osseointegration, little is know about this issue in the context of stemless shoulder implants. Considering 3D finite element models, the purpose of this study was to evaluate the primary stability of five stemless designs, based on the Sidus, SMR, Simpliciti, Eclipse, and Global Icon stemless systems. Three alternative bone quality conditions were considered for cancellous bone. For the Sidus, SMR, and Simpliciti designs, which do not possess a collar that sits on the cortical rim of the humeral resected surface, contact and no contact conditions were considered between the bone surface and the humeral head components. Micromotions at bone-implant interfaces promoting osseointegration were computed as a measure of primary stability for eight load cases consisting of peak in vivo joint loads measured during selected upper limb activities. Under good bone quality conditions, all stemless designs presented micromotions below 150 μm. The Eclipse-based and Global-Icon based designs were the least sensitive to bone quality. Stemless designs presenting a solid collar or contact between the humeral head component and bone provided more stability. Overall, the Eclipse-based and Global Icon-based designs presented the best performance from the primary stability point of view. However, if bone adaptation data available in the literature are considered along with the primary stability data computed here, the Global Icon-based design, as well as other designs, might be considered superior long-term options due to their better compromise between primary stability and impact on bone adaptation.

Screw fixation in stemless shoulder arthroplasty for the treatment of primary osteoarthritis leads to less osteolysis when compared to impaction fixation

Background

Stemless total shoulder arthroplasty is a well-established and reliable surgical treatment option for glenohumeral osteoarthritis resulting in loss of pain and improvement of shoulder function. Currently the two methods for the fixation of the humeral component are either screw fixation or impaction. The purpose of this study is the clinical and radiological comparison of two different stemless designs (screw fixation vs impaction) for total shoulder arthroplasties in patients suffering from primary glenohumeral osteoarthritis.

Methods

A retrospective cohort study including 39 patients with a mean age of 67 years and a minimum follow-up of 2 years was performed. Patients were separated into two groups based on the selected implant. In group A (n = 18) a screw fixation design and in group B (n = 21) an impaction type design was used. For clinical examination the Constant-Murley-Score (CS) and Subjective-Shoulder-Value (SSV) were evaluated. Radiological examination was performed on true-AP, axial and Y-view radiographs.

Results

In group A the CS increased from 27.1 to 65.2 points and SSV from 27.3 to 76.7% (p > 0.05). No osteolysis of the medial calcar or subsidence of the humeral implant were found in this group. In group B the CS increased from 29.0 to 72.6 points and SSV from 33.1 to 85% (p < 0.05). Osteolysis of the medial calcar was present in seven patients in this group. No signs for humeral loosening were found in both groups.

Conclusion

Impaction and screw fixation total shoulder arthroplasty for primary glenohumeral osteoarthritis using a stemless device provide reliable clinical results. The screw fixation seems to prevent osteolysis of the medial calcar.

The short- to midterm effectiveness of stemless prostheses compared to stemmed prostheses for patients who underwent total shoulder arthroplasty: a meta-analysis

BACKGROUND

To systematically compare the short- to midterm effectiveness of stemless prostheses to that of stemmed prostheses for patients who underwent total shoulder arthroplasty (TSA) and to provide a guideline for clinical decision-making.

METHODS

PubMed, the Cochrane Library, and Web of Science were searched with the given search terms until July 2019 to identify published articles evaluating the clinical outcomes for stemless prostheses compared with stemmed prostheses for patients who underwent TSA. Data extraction and the quality assessment of the included studies were independently performed by two authors. Stata software 14.0 was used to analyze and synthesize the data.

RESULTS

Two randomized controlled trials and six case-controlled studies with a total of 347 shoulders were included in this meta-analysis. The results of this meta-analysis showed that there were no significant differences between the stemless and stemmed prostheses in terms of the Constant score, pain score, strength, activities of daily living, postoperative range of motion (ROM), and postoperative maximum active ROM.

CONCLUSIONS

This is the first meta-analysis reporting the clinical results of stemless TSA in the short- to midterm follow-up period. Both types of shoulder prostheses were similar in achieving satisfactory clinical outcomes.

Reliability of stemless shoulder arthroplasty in rheumatoid arthritis: observation of early lysis around the humeral component

PURPOSE

To evaluate whether stemless shoulder implants in rheumatoid arthritis (RA) patients provide comparable functional outcomes to patients with osteoarthritis or post-traumatic arthritis. In addition, the study assessed for differences in incidence of radiolucent lines or proximal humeral bone loss during radiographic follow-up.

METHODS

Consecutive stemless shoulder arthroplasties performed in RA patients and a matched control group were retrospectively identified between February 2012 and 2018. Thirty-five patients were included in each group: 24 total shoulder arthroplasty (TSA) and 11 hemiarthroplasty (HA). Patients were evaluated annually using the Oxford Shoulder Score (OSS) and radiographically.

RESULTS

The mean OSS significantly improved in all groups until 24 months. The mean improvement for RA TSA and HA patients at 24 months was 19.86 (95% CI 10.66-29.05, p = 0.0004) and 19.71 (95% CI 7.33-32.31, p = 0.0084), respectively. The mean improvement in the control TSA and HA patients at 24 months was 20.86 (95% CI 17-24.71, p = 0.0001) and 17.86 (95% CI 1.36-34.35, p = 0.0381), respectively. During the study period, two patients in the RA TSA group (8%), one patient in the control TSA group (4%) and one patient in the control HA group (9%) required revision. The proportion of progressive proximal humeral bone loss after TSA was 33% in the RA group and 13% in the control group.

CONCLUSION

Stemless shoulder implants can provide significant improvement in functional scores in RA patients in the short term. However, early bone loss around the humeral implant is a concern and the authors recommend long-term clinical and radiological follow-up.

Do the radiological changes seen at mid term follow up of stemless shoulder prosthesis affect outcome?

Background

The Eclipse® (Eclipse® is a trademark of Arthrex, Naples, Florida) stemless shoulder prosthesis offers the surgeon the advantage of bone stock preservation and at the same time avoids the drawbacks of a resurfacing arthroplasty. Previous studies have shown radiographic changes on serial follow up of the Eclipse prosthesis. This study attempts to assess the significance of these radiographic changes and effect of cuff related pathology on the mid-term outcome of the Eclipse prosthesis.

Methods

Between July 2005 and October 2008, 29 shoulders underwent shoulder arthroplasty with the Eclipse prosthesis; 23 shoulders, (seven women and 16 men) were available for the final follow up. The range of motion, Constant Score; age adjusted Constant Score, Subjective Shoulder Value and radiographs were assessed at serial follow-ups.

Results

Significant improvements were seen in the Constant Score (78.9 ±20.1) compared to pre-operative score (32.9 ±5.2); also forward elevation, abduction and external rotation improved to 142.9 ± 36.6 °, 135.2 ± 40.5 ° and 49.8 ± 21.9 ° at 72 months (p < 0.001). Radiolucent lines and localised osteopenia, did not statistically impact on the clinical outcome. Partial tears of the supraspinatus and subscapularis had a negative impact on the Subjective Shoulder Value (p < 0.05) Partial or complete tears of the subscapularis led to worse Constant Score on follow up (p < 0.05).

Conclusions

The presence of radiolucent lines or localised osteopenia does not influence the mid term clinical outcome. Pre -operative partial supraspinatus tears or tears of the subscapularis lead to an inferior outcome.

Bone adaptation impact of stemless shoulder implants: a computational analysis

BACKGROUND

Despite stemless implants showing promising functional and radiologic clinical outcomes, concerning signs of complications, such as bone resorption, have been reported. The aim of this study was to investigate the influence of 5 stemless designs on the bone adaptation process of the humerus.

METHODS

Three-dimensional finite element models of shoulder arthroplasties were developed considering stemless designs based on the Eclipse, Global Icon, SMR, Simpliciti, and Sidus stemless systems. For the designs not possessing a collar that covers the entire resected surface of the humerus, conditions of contact and no contact were simulated between the humeral head components and the bone surface. By use of a bone remodeling model, computational simulations were performed considering 6 load cases of standard shoulder movements. The bone adaptation process was evaluated by comparing differences in bone density between the implanted models and the intact model of the humerus.

RESULTS

Overall, the design of the stemless implants had a relevant impact on the bone adaptation process of the humerus. The Eclipse-based design caused the largest bone mass loss, whereas the SMR-based design caused the least. When contact was simulated between the humeral head components of the SMR-, Simpliciti-, and Sidus-based designs and the resected bone surface, bone resorption increased.

DISCUSSION

Considering only the bone adaptation process, the results suggest that the SMR-based implant presents the best performance and that contact between the humeral head component and the resected bone surface should be avoided. However, because other factors must be considered, further investigation is necessary to allow definite recommendations.

Total shoulder arthroplasty with nonspherical humeral head and inlay glenoid replacement: clinical results comparing concentric and nonconcentric glenoid stages in primary shoulder arthritis

Background

Glenoid morphology can influence the outcomes of total shoulder arthroplasty. This study examines the results of a new technique according to preoperative glenoid staging. We hypothesized that there would be no statistically significant difference in outcomes between Levine concentric (Walch A) and Levine nonconcentric (Walch B) glenoids treated for primary glenohumeral arthritis using nonspherical humeral head and inlay glenoid replacement.

Methods

This retrospective case series included 31 shoulders in 29 patients (25 male, 4 female), with an average age of 58.5 years. Outcomes included the Penn Shoulder Score (PSS), visual analog scale for pain (VAS-Pain), range of motion, radiographic analysis, and complications. Inclusion criteria were primary glenohumeral arthritis, intact rotator cuff, and no prior open shoulder surgeries.

Results

Mean follow-up was 42.6 months (range, 24-74 months). The study included 7 concentric and 24 nonconcentric glenoids. Outcomes comparison showed no statistically significant differences in PSS domains including Pain (P = .92), Function (P = .98), Satisfaction (P = .89), and Total (P = .98); forward flexion (P = .78); external rotation (P = .64); and VAS-Pain (P = 0.12). At the last follow-up, the mean PSS Pain was 25.3/30, Function 52.7/60, Satisfaction 8.4/10, and Total 87.0/100. The mean forward flexion was 167.3°, external rotation 56.6°, and VAS-Pain 0.9. There were no signs of periprosthetic fracture, component loosening, osteolysis, and hardware failure, and no revisions or 90-day rehospitalizations were required. One patient was prophylactically treated with oral antibiotics for a history of prior infection and 1 patient required a later open biceps tenodesis after a traumatic proximal biceps rupture postoperatively.

Conclusion

Nonspherical shoulder arthroplasty with inlay glenoid replacement demonstrated excellent clinical benefits for both concentric and nonconcentric glenoids. The technique appears to be a promising option for glenohumeral arthritis even in the presence of posterior glenoid erosion.

Radiographic restoration of native anatomy: a comparison between stemmed and stemless shoulder arthroplasty

BACKGROUND

Shoulder arthroplasty is a reliable procedure for patients with degenerative glenohumeral disease, and reproduction of native shoulder anatomy leads to superior outcomes. The aim of this study was to compare the ability of stemmed and stemless implants to radiographically restore native glenohumeral anatomy.

METHODS

Shoulder arthroplasties were performed in 79 patients, with 58 receiving a stemless implant and 21 receiving a stemmed implant. Preoperative and postoperative radiographs were assessed for humeral head height, humeral head centering, humeral head medial offset, humeral head diameter, humeral neck angle, and lateral humeral offset by 2 independent viewers. Measurements were scored and summed to identify the anatomic reconstruction index (ARI). Radiographic measurements were compared using the Student t test, and significance was set at P < .05 for all statistical analyses. Interobserver agreement of radiographic analyses was assessed using the intraclass correlation coefficient, finding excellent reliability (intraclass correlation coefficient, 0.92).

RESULTS

Five of six radiographic measurements along with the calculated ARI demonstrated no differences between stemmed and stemless shoulder implants (humeral head diameter, P = .651; humeral head height, P = .813; humeral head medial offset, P = .592; lateral humeral offset, P = .311; humeral head centering, P = .414; and ARI, P = .862). Stemless implants showed improved restoration of the native humeral neck angle (0° for stemless vs. -3° for stemmed, P = .017).

CONCLUSION

Radiographic restoration of anatomy is similar for stemmed and stemless shoulder arthroplasty implants.

Patient-reported outcome after stemmed versus stemless total shoulder arthroplasty for glenohumeral osteoarthritis: a patient-blinded randomized clinical trial

BACKGROUND

Stemless shoulder arthroplasty systems with uncemented metaphyseal fixation have been used for glenohumeral osteoarthritis since 2004 (Hawi, et al. BMC Musculoskelet Disord 17:376, 2016). The stemless design has several theoretical advantages compared with the stemmed shoulder arthroplasty systems: restoring patients' anatomy; preserving humeral bone stock; and few complications in component removal if the need for a revision arthroplasty arises. The purpose of the study is to compare the short-term, patient-reported outcome of stemless and stemmed total shoulder arthroplasty (TSA).

MATERIALS AND METHODS

A randomized clinical trial will be conducted. Eighty patients with clinical and radiological signs of primary or post-traumatic glenohumeral osteoarthritis, computed tomography (CT) scan-verified adequate glenoid bone stock, and no total rupture of rotator cuff tendons verified by a magnetic resonance imaging (MRI) scan will be randomly allocated to a stemless or stemmed TSA. The primary outcome will be the Western Ontario Osteoarthritis Shoulder (WOOS) score at 12 months. Secondary outcomes are the WOOS score at three months and the Oxford Shoulder Score (OSS) and EQ-5D at 3 and 12 months. All complications, including glenoid and humeral component loosening, instability, rotator cuff tear, intraoperative and postoperative periprosthetic fracture, nerve injury, infection, deltoid injury, and symptomatic deep venous thrombosis, will be reported.

DISCUSSION

Findings will provide patients with better information about the potential benefits and harms of stemless and stemmed TSA and will assist shoulder surgeons and patients in decision-making.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT03877315 . Registered on 13 March 2019.

Short-term results of total shoulder arthroplasty for ochronotic arthritis

Alkaptonuria is a rare inherited autosomal recessive disorder resulting in large joint osteoarthritis with black discoloration of the cartilage. The glenohumeral is the third most affected joint. Two cases of ochronotic shoulder arthropathy with three shoulder joint replacements are presented. Stemless shoulder arthroplasty was implanted with moderate to good results up to 2 years follow-up regarding pain and range of motion.

Cementless metaphyseal reverse shoulder arthroplasty: our preliminary experience

Reverse shoulder arthroplasty (rTSA) is a largely used procedure with a wide variety of indications. The incidence of this surgery is increased in recent years and the literature expects similar trend for the future. Metaphyseal stem rTSA seems to be a promising solution considering major objectives the preservation of humeral bone stock and ease of revision. In our study we analyzed 19 patients treated with cementless metaphyseal stem rTSA for osteoarthritis (group A) and acute fractures (group B). In group A (7 patients) the average Constant score improved from 21,57 (16-29) to 56,85 (38-72), the average SST improved from 2,29 (1-4) to 9,43 (8-12) and the mean VAS score improved from 14,29 to 4,86. In group B (12 patients) the mean Constant-Murlay score at last follow up was 42,17; the average SST was 7 and average pain score was 8,92. Overall active range-of-motion (ROM) improved significantly. Surgical considerations, clinical (analyzing Constant score and Simple Shoulder Test) and radiological short-term outcomes are encouraging, with low rate of complications. Long term follow-up studies are necessary to confirm our findings and the potential benefits related to these implants. (www.actabiomedica.it)

Clinical and radiologic outcomes following total shoulder arthroplasty using Arthrex Eclipse stemless humeral component with minimum 2 years' follow-up

BACKGROUND

Stemless humeral components benefit from less morbidity, better reproduction of the humeral anatomy, ease of revision, and fewer stem-related complications. Encouraging results are available up to 9 years after surgery from the designer's series. This is an independent study of 100 consecutive Eclipse stemless prostheses for osteoarthritis with a minimum 2-year follow-up (range, 2-6 years).

METHODS

We included only total shoulder arthroplasties performed for osteoarthritis. The primary outcome was the Oxford Shoulder Score (OSS) after 2 years. Secondary outcome measures were change in shoulder range of movement and radiographic analysis of prosthesis size and position.

RESULTS

The mean OSS at 2 years was 38 of 48, with a mean improvement of +19 points (range, +17 to +22 points; P < .001). There was no significant deterioration in OSS after 3 or 4 years' follow-up. Statistically significant improvement was seen in arm elevation and external rotation (P < .001). There were 5 reoperations-1 for impingement of the biceps stump and 4 revisions to reverse arthroplasty for cuff failure. Of the prostheses, 92% were sized within 2 mm of the anatomic head size, and in 76% of prostheses, the center of rotation was within 3 mm of the native anatomy. An incomplete radiolucent line was present in zone B (around the cage screw) in a single patient at 2 years following surgery. There were no cases of loosening or infection.

CONCLUSION

The functional and radiographic outcomes of Eclipse total shoulder replacement are excellent. We were able to accurately reproduce the native anatomy in the majority of cases, with no implant loosening, at 2 to 6 years' follow-up.

Bone remodelling of the humerus after a resurfacing and a stemless shoulder arthroplasty

BACKGROUND

New implant designs, such as resurfacing and stemless implants, have been developed to improve the long-term outcomes of the shoulder arthroplasty. However, it is not yet fully understood if their influence on the bone load distribution can compromise the long-term stability of the implant due to bone mass changes. Using three-dimensional finite element models, the aim of the present study was to analyse the bone remodelling process of the humerus after the introduction of resurfacing and stemless implants based on the Global C.A.P. and Sidus Stem-Free designs, respectively.

METHODS

The 3D geometric model of the humerus was generated from the CT data of the Visible Human Project and the resurfacing and stemless implants were modelled in Solidworks. Considering a native humerus model, a humerus model with the resurfacing implant, and a humerus model with the stemless implant, three finite element models were developed in Abaqus. Bone remodelling simulations were performed considering healthy and poor bone quality conditions. The loading condition considered comprised 6 load cases of standard shoulder movements, including muscle and joint reaction forces estimated by a multibody model of the upper limb.

FINDINGS

The results showed similar levels of bone resorption for the resurfacing and stemless implants for common humeral regions. The regions underneath the head of the resurfacing implant, unique to this design, showed the largest bone loss. For both implants, bone resorption was more pronounced for the poor bone quality condition than for the healthy bone quality condition.

INTERPRETATION

The stemless implant lost less density at the fixation site, which might suggest that these implants may be better supported in the long-term than the resurfacing implants. However, further investigation is necessary to allow definite recommendations.

Primary Shoulder Hemiarthroplasty: What Can Be Learned From 359 Cases That Were Surgically Revised?

BACKGROUND

Primary shoulder hemiarthroplasty is used to address a range of glenohumeral disorders, including fracture, arthritis, avascular necrosis, and capsulorrhaphy arthropathy; some patients with hemiarthroplasties undergo revision surgery for persistent pain or residual shoulder dysfunction. The literature does not clarify the features of the hemiarthroplasties having repeat surgery in a way that can guide surgeons' efforts to minimize the need for revision. To help address this gap, we analyzed the characteristics of patients from our region for whom we performed surgical revision of a prior humeral hemiarthroplasty QUESTIONS/PURPOSES: (1) What are the common characteristics of shoulder hemiarthroplasties having a revision? (2) What are the common characteristics of the subset of revised shoulder hemiarthroplasties that were performed for fracture? (3) What are characteristics of the subset of all revised hemiarthroplasties that were associated with glenoid bone erosion?

METHODS

Data for 983 patients for whom we performed a surgical revision of any type of shoulder arthroplasty between January 1991 and January 2017 were identified in our longitudinally maintained institutional arthroplasty revision database. In each case, revision had been elected by shared patient and surgeon decision-making after consideration of the disorder, degree of compromised comfort and function, treatment alternatives, and the risks of surgery. Of these 983 patients, 359 (37%) had a revision of a prior primary hemiarthroplasty; these patients were the subjects of this investigation. In this group of patients, we investigated the patient demographics, shoulder characteristics, prerevision radiographic findings, and findings at revision surgery. No patients were excluded. The patients having revision of primary hemiarthroplasties had severe loss of self-assessed shoulder comfort and function, with Simple Shoulder Test (SST) scores averaging 2.2 ± 2.2 of the maximum score of 12. The majority of these patients (81%) were women. The medical records of these 359 patients were abstracted to determine the diagnosis for the index primary hemiarthroplasty, clinical characteristics before surgery, and findings at surgical revision. One hundred twelve of the arthroplasties had been performed for fracture-related diagnoses; a subgroup analysis was performed on these patients. Two hundred seventy-three of the 359 patients (76%) had plain radiographs performed within 3 months before revision surgery that were adequate for assessing the radiographic characteristics of the glenoid, humerus, humeral component, and glenohumeral relationships; a subgroup analysis was performed on these patients. The degree of glenoid erosion was measured by a single observer in accordance with established criteria: Grade 1 is no erosion, Grade 2 is erosion limited to subchondral bone, Grade 3 is moderate erosion with medialization, and Grade 4 is medialization beyond the coracoid base. Some patients were included in both of these subgroups.

RESULTS

Common characteristics of the revised hemiarthroplasties included female sex (81%), rotator cuff (89 of 359; 25%) or subscapularis (81 of 359; 23%) failure, problems related to prior fracture (154 of 359; 43%), glenoid erosion 125 of 359; 35%), and component malposition (89 of 359; 25%). Hemiarthroplasties performed for fracture-related problems often were associated with tuberosity malunion or nonunion (58 of 79; 73%) and decentering of the humeral component on the glenoid surface (45 of 71; 63%). Major erosion of the bony glenoid (Grade 3 or 4) was more common in decentered hemiarthroplasties (42 of 102; 41%) than for centered hemiarthroplasties (36 of 146; 25%) (Fisher's exact p = 0.008) and more common for hemiarthroplasties positioned in valgus (28 of 50; 56%) than for those positioned in neutral or varus (40 of 188; 21%) (Fishers' exact p < 0.0001).

CONCLUSIONS

These findings suggest that some revisions of primary hemiarthroplasties may be avoided by surgical techniques directed at centering the prosthetic humeral articular surface on the glenoid concavity using proper humeral component positioning and soft tissue balance, by avoiding valgus positioning of the humeral component, and by managing glenoid disorders with a primary glenohumeral arthroplasty rather than a hemiarthroplasty alone. When durable security of the subscapularis, rotator cuff, and tuberosities is in question, the surgeon may consider a reverse total shoulder arthroplasty.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Bleeding in primary shoulder arthroplasty

INTRODUCTION

The aim of this investigation was to analyse "total blood loss" (TBL), "blood transfusion rate" (BT) and the "amount of transfused blood units" (BU) between the different primary shoulder arthroplasty (SA) types: reverse, anatomical and stemless. Only primary SA was included. Further goal was to identify risk factors for TBL, amount of BU and BT rate.

METHODS

A retrospective charts analysis of patients who received primary SA for degenerative shoulder pathology in our institution between 2004 and 2016 was performed. The demographic data, co-morbidities, haemoglobin and hematocrit level, BT rate, amount of transfused BU etc. were collected. TBL was estimated. Linear regression, log-linear poisson regression and logistic regression were used to compare the outcomes TBL, amount of transfused BU and BT rate, respectively, between different prosthesis types.

RESULTS

Of 278 patients included in this study 209 received reverse, 57 anatomical and 12 stemless SA. Mean TBL was 392.7 ml in reverse, 394.6 ml in anatomical and 298.3 ml in stemless SA. The BT rate and mean amount of BU were, respectively, 14.4% and 0.32 in reverse and 8.77% and 0.23 in anatomical SA. None of the patients with stemless arthroplasty received BT. Significant risk factors for elevated TBL are operation time, higher BMI, male sex. Significant risk parameters for BT and higher amount of transfused BU are low BMI, cemented arthroplasty, coronary heart disease, ASA score > 2 and previous therapy with vitamin K antagonists.

CONCLUSION

Although there were little differences between the blood transfusion rates in reverse vs. anatomical arthroplasty, there was no difference in total blood loss between these different prosthesis types. None of the patients with stemless arthroplasty received blood transfusion. There are various risk factors affecting total blood loss and blood transfusion rate. However, risk parameters influencing blood transfusion may be different to them affecting total blood loss.

Restoration of the joint geometry and outcome after stemless TESS shoulder arthroplasty

AIM

To evaluate the joint geometry and the clinical outcome of stemless, anatomical shoulder arthroplasty with the TESS system.

METHODS

Twenty-one shoulders with a mean follow-up 18 of months were included. On scaled digital radiographs the premorbid center of rotation (CoR) was assessed and compared to the CoR of the prosthesis by using the MediCAD^® software. Additionally, the pre- and post-operative geometry of the CoR was assessed in relation to the glenoid, the acromion as well as to the proximal humerus. Radiological changes, such as radiolucencies, were also assessed. Clinical outcome was assessed with the Constant and DASH score.

RESULTS

Both, the Constant and DASH scores improved significantly from 11% to 75% and from 70 to 30 points, P < 0.01 respectively. There were no significant differences regarding age, etiology, cemented or metal-backed glenoids, etc. (P > 0.05). The pre- and postoperative humeral offset, the lateral glenohumeral offset, the height of the CoR, the acromiohumeral distance as well as neck-shaft angle showed no significant changes (P > 0.05). The mean deviation of the CoR of the prosthesis from the anatomic center was 1.0 ± 2.8 mm. Three cases showed a medial deviation of more than 3 mm. These deviations of 5.1, 5.7 and 7.6 mm and were caused by an inaccurate humeral neck cut. These 3 patients showed a relatively poor outcome scoring.

CONCLUSION

TESS arthroplasty allows an anatomical joint reconstruction with a very good outcome. Outliers described in this study sensitize the surgeon for an accurate humeral neck cut.