Shoulder arthroplasty in Germany: 2005-2012

Reverse total shoulder arthroplasty policy in Germany - an analysis of the health care reality from 2010 to 2022

BACKGROUND

The last few years have been characterized by increasing numbers of reverse shoulder arthroplasties. In addition to the classic indication of cuff tear arthropathy, the use for complex proximal humeral fractures (PHFs) and rotator cuff tear (RCT) in very old patients have been established. The objective of this study is to clarify and substantiate the above statements specifically for Germany (based on official data from 2010 to 2022). Since substantial changes in the structure of the population are expected over time, all data must be adjusted for these changes. The hypotheses are (1) the German population is ageing with a shift to more elderly patients over time, and (2) the general use of shoulder arthroplasty (total anatomic - shoulder arthroplasty (aTSA) and reverse - rTSA) has increased during the time period, but the effect is beyond the shift of age stratification but attributable to a change of hospital admissions and surgical therapy for PHF and RCT.

METHODS

In this retrospective study, data were collected from the National Bureau of Statistics in Germany for the period of 2010 to 2022. Three different data sources were combined for the analysis: a database regarding the structure of the population in age groups for every year, a database reporting relevant operation codes, and the data on hospital admissions based on ICD-10 codes. The relevant data were extracted and combined using Excel spread sheets (Microsoft Corporation, version 2019). Absolute numbers are reported and adjusted for 100.000 inhabitants in each age group in order to calculate the incidence.

RESULTS

Only slight change in absolute numbers of the population (n = 81751602 to 84358845, +3%) was observed, but a substantial shift toward the group of elderly people: the peak age group has shifted from 40-50 to 55-65. The number of TSA has significantly increased (n = 15000 to n = 28117, +187%; incidence 18.35 to 28.53, +155%). The number of rTSA has largely increased (n = 5326 to n = 24067, +452%; incidence 6.51 to 28.53, +438%), whereas the number of aTSA steadily decreased (n = 9674 to n = 4050, -42%; incidence 11.83 to 4.80, -41%). The number of revision arthroplasties has increased 1.8-fold (n = 2179 to n = 3893; incidence 1.7-fold). The peak revision rate shifted from the age group 70-75 toward 90- 95; 76% of all revision cases were performed in patients 65 years and older in 2010 increasing to 87% in 2022. Hospital admissions for PHF have increased 7.8-fold (n = 110091 to n = 810907). The peak in the age groups has shifted by a decade from 70-74 to 80-84. The absolute number of surgical therapy for PHF has decreased (n = 12816 to n = 9562, 75%; incidence 72%). The number of hospital admissions for RCT increased by 2.6-fold (n = 47004 to n = 124096; incidence + 255%). The number of surgical interventions for RCT increased by 3.7% (n = 51350 to n = 53294; incidence 62.8 to 63.2). Combined numbers for the operative therapy of PHF, RCT, and rTSA show an increase of +124% (n = 69491 to n = 86715) with a peak shift on one decade toward the age group 60-94 with 79% of the patients in 2022. The increased use of rTSA, as expressed by incidence, is strongly correlated with the increasing proportion of people aged 65 and over.

CONCLUSION

The data show a substantial increase in the use of shoulder arthroplasty procedures in Germany in the observed time period, with the main driving factor being the increase of rTSA, whereas aTSA numbers decreased. The combined analysis of the hospital admissions and operative procedures performed to treat PHF and RCT indicated a shift of treatment numbers from open reduction and internal fixation and rotator cuff repair in the elderly toward the alternative use of rTSA in this age group. The observed shift of the stratification of age groups gives a further explanation for the increase in rTSA use: the number of patients in the age groups with the typical and alternative indications for rTSA substantially increased with a shift of the peak age group towards the elderly of one decade. Healthcare officials should be aware of these fundamental changes in the population, which create further demands on the health care system. The expected continuation of rising numbers of rTSA needs to be addressed by providing adequate resources such as reimbursement, surgical and rehabilitation facilities, and staff.

Trends in Shoulder Arthroplasty in Germany: A 10-Year Epidemiological Analysis of Patients with Primary Osteoarthritis of the Shoulder

Shoulder arthroplasty has significantly gained popularity in orthopedic surgery, driven by progress in prosthesis design and surgical techniques. This study explored the epidemiology of shoulder arthroplasty, analyzing healthcare data from 2012 to 2022 for primary osteoarthritis of the shoulder. The data included patient demographics and types of surgical procedures. Data analysis indicates a higher utilization rate of reverse total shoulder arthroplasty (RTSA; n = 41,251) over total- (TSA; n = 18,679) and hemiarthroplasty (HSA; n = 12,827) for primary shoulder osteoarthritis. Overall, a significant increase in RTSA procedures from n = 2237 (2012) to n = 5415 (2022) was observed, representing more than a two-fold increase of 121.1%. The relative proportion of RTSA among all types of shoulder arthroplasty increased from 39% (2012) to 68.6% (2022), while HSA decreased and TSA essentially remained constant. Age analysis identified the following peaks: RTSA, 77 ± 7 y; HSA, 68 ± 12 y; and TSA, 67 ± 10 y. Among the over 60s, significantly more women were treated with any type of prosthesis, whereas in young patients (45 to 59 y), more men received HSA or TSA. Our study confirms that RTSA has become the preferred choice for elderly patients in Germany, reflecting the prevailing preference despite varying patient ages and conditions, with a noted difference in sex in treatment prevalence.

What is the middle term survival of reverse shoulder arthroplasty? A retrospective observational registry-based study

PURPOSE

The use of reverse total shoulder arthroplasty has increased over the last decade. Like any other implant it is associated with complications sometimes leading to revision. We carried out a registry-based study in order to find possible risk factors associated with the need of revision surgery.

METHODS

The RIPO registry was analyzed from July 2008 to December 2018 collecting available data. Two groups (degenerative or fracture) were formed and compared to determine possible risk factors difference in revision surgery.

RESULTS

A total of 7,966 shoulder prosthesis were implanted. There was a 1.5% intra or peri-operative complication rate. The revision rate was 4.0% at a mean follow-up of 4.4 years. A total of 3,073 reverse total shoulder prosthesis were implanted and available for follow-up. An increase of revision rate (the most frequent causes being aseptic loosening, infection and instability) was found in patients younger than 65 years and in male patients. Two groups were then formed on the basis of the primary diagnosis: osteoarthritis and proximal humerus fracture. Comparison between the two groups showed an increase in instability requiring revision in the fracture group.

CONCLUSION

Reverse shoulder prosthesis is a valid treatment option both in the elective and in the trauma settings, but young and male patients should be informed of the inherently increased risk of revision and prosthesis used in the fracture setting should be evaluated more thoroughly to prevent instability.

The impact of tobacco use on clinical outcomes and long-term survivorship after anatomic total shoulder arthroplasty

Introduction

Postoperative outcomes following total shoulder arthroplasty can be affected by preoperative health factors such as tobacco usage.

Methods

The charts of patients who underwent anatomic total shoulder arthroplasty were retrospectively analyzed and stratified based on smoking status. The primary data included range of motion and patient reported outcomes. Additionally, demographic, radiographic, and survivorship analyses were conducted. All data were analyzed using statistical inference.

Results

There were 78, 49, and 16 non-smoker, former smoker, and current smoker shoulders respectively with no significant differences in sex, American Society of Anesthesiologists status, body mass index, or mean follow-up time (average: 10.7 yrs). Smokers (51.5 ± 10.4 years) were younger than both non-smokers (64.9 ± 8.1 years; p < 0.01) and former smokers (65.1 ± 9.1years; p < 0.01) at the time of surgery. For non-smokers and former smokers, all range of motion and patient reported outcome scores significantly improved. Smokers reported significant improvements in all patient reported outcomes and external and internal rotation. Visual Analog Scale, American Shoulder and Elbow, and Simple Shoulder Test scores were lower for smokers comparatively, but these differences did not reach significance. Forward elevation was higher postoperatively for non-smokers (149.7o ± 17.2o) and former smokers (147.1o ± 26.0o) compared to current smokers (130.9o ± 41.2o; p = 0.017). No differences between the cohorts were found in the radiographic analysis. Revision rates were lower in the non-smoking cohort (7.7%) compared to both former (20.4%; p = 0.036) and current smokers (37.5%; p < 0.01). Survival curves showed that non-smoker implants lasted longer than those of current smokers.

Conclusion

After a decade, patients generally had improved shoulder range of motion, functionality, and pain regardless of smoking status. However, current smokers required shoulder replacements sooner and revision surgery more frequently.

Shoulder replacement: an epidemiological nationwide study from 2009 to 2019

Background

Shoulder replacement (SR) constitutes the gold standard treatment for severe shoulder diseases, including osteoarthritis, rheumatoid arthritis, complex fractures, avascular necrosis and rotator cuff arthropathy. Although several countries have national registries, there is a lack of epidemiological data on SR. Sharing national statistics and correlating those to other countries could be helpful to compare outcomes and costs internationally. This paper aims to evaluate the trend of hospitalizations for SR (both first implants and revisions of anatomical and reverse prosthesis) in Italy from 2009 to 2019, based on the National Hospital Discharge Reports (S.D.O) provided by the Italian National Health Service (INHS). Moreover, the economic impact on the healthcare system of SR and SR revisions was assessed, providing a statistical prediction for the next ten years.

Methods

The data used in this paper were about patients who underwent Total Shoulder Replacement (TSR), Shoulder Hemiarthroplasty (SH) or Revision of shoulder joint replacement (RSR) from 2009 to 2019 in Italy. Information about patients was anonymous and included age, sex, days of hospitalization, procedures and diagnoses codes.

Results

From 2009 to 2019, 73,046 TSR and SH were performed in adult Italian residents, with a cumulative incidence of 13.6 cases per 100,000 adult Italian residents. While, 2,129 revisions of shoulder replacement were performed, with a cumulative incidence of 0.4 cases per 100,000 residents. Overall, females represented the majority of the cases (72.4% of patients who underwent TSR or SH and 59.1% of patients who underwent RSR). From 2009 to 2019, has been assessed an overall cost of 625,638,990€ for TSR or SH procedures in Italy. While, an overall cost of 9,855,141€ for RSR procedures in Italy was calculated.

Conclusions

The incidence of SR and RSR is expected to increase in the following years, constituting a burden for the healthcare systems. Overall, in Italy, the females represented the majority of patients. Further prospective studies on this topic in different countries can be con-ducted to make comparisons.

Standard radiological classification of glenohumeral osteoarthritis does not correlate with the complexity of the arthritic glenoid deformity

BACKGROUND

The Samilson-Prieto classification (SPC) depending on the humeral osteophyte length on a-pX-rays today is widely used to classify glenohumeral osteoarthritis in general. For treatment planning and prognosis, the patho-morphology of the glenoid and static posterior subluxation of the humeral head classified according to Walch is of much higher importance. Here, usually a CT or MRI scan is required for a correct classification. A possible correlation between both classifications is poorly explored. Without it, the complexity of the case might be mis-interpreted using the SPC. The aim of this study was to investigate such a correlation, i.e. whether it correlates with the glenoid deformity and degree of humeral head subluxation.

PATIENTS AND METHODS

Radiological datasets (X-ray and CT or MRI) of 352 patients with primary OA of the shoulder were evaluated by two observers experienced in shoulder surgery. For the Samilson-Prieto classification, true a-p shoulder radiographs and for the modified Walch classification CT or MRI scans in the axial plane were interpreted using a validated method. To investigate a correlation between both classifications, the Fisher's exact test was used. For the interobserver reliability, the weighted kappa coefficient κ was determined.

RESULTS

For the Walch classification, both observers found a similar percentage for the different types, with decreasing numbers from normal (type A1) to severely altered glenoids In the Samilson-Prieto classification, OA grade I was predominant, while grade II and III showed a relatively equal distribution. Interobserver reliability was high both for the Walch classification with a κ 0.923 (95% confidence interval 0.892; 0.954) and) for the SPC with a κ 0.88 (95% confidence interval 0.843; 0.916). A correlation between the two classifications in Fischer's exact test could not be shown (p = 0.584).

DISCUSSION

Since there is no correlation between both, using the Samilson-Prieto classification alone might miss relevant prognostic factors in gleno-humeral OA. Adequate imaging of the glenoid morphology also in the axial plane is absolutely mandatory to understand the complexity and chose the right treatment for each patient.

LEVEL OF EVIDENCE

Study of Diagnostic Test-Level II.

[3D printing in the field of shoulder surgery]

The 3D printing technology is a relatively new procedure with a high potential, especially in the field of shoulder surgery. The 3D printing procedures are increasingly being developed and also gaining new users. Principally, 3D printing procedures can be applied preoperatively in planning the surgical procedure, patient clarification and in teaching; however, the technology is increasing being used intraoperatively. In addition to intraoperative visualization of the models, 3D printing permits the use of individual and specific instruments and implants. This allows the precise transfer of the preoperative planning to the surgical procedure. Inaccuracies are mainly caused by soft tissues. The 3D printing can be beneficial in the fields of arthroplasty, shoulder instability as well as orthopedic trauma. The literature shows promising results in relation to duration of surgery, blood loss and clinical results of the procedure. On the other hand, it is still unclear which indications warrant the use of 3D printing. Other aspects that raise questions are the time of planning, the production time and the additional cost that the use of 3D printing entails. Nonetheless, 3D printing represents a meaningful enhancement of the portfolio of surgeons, which becomes highly beneficial and useful in complex situations. Furthermore, this procedure enables a certain amount of flexibility when reacting to certain circumstances.

Mid-term outcomes of a stemless ceramic head anatomic total shoulder replacement

Background

In an anatomic shoulder replacement (aTSR) good results have been reported with the use of a stemless humeral prosthesis. In vitro a ceramic articulation with polyethylene has been shown to produce less polyethylene wear particles than with metal. This study aims to evaluate clinical and radiographic results of a stemless aTSR with a ceramic head articulating with a polyethylene glenoid component, with mid-term follow-up.

Methods

All patients (n = 92) in this prospective study had an aTSR utilizing a stemless humeral component with a ceramic head and a cemented double pegged cemented polyethylene glenoid component for glenohumeral osteoarthritis. Pre- and postoperative clinical evaluations at 2 years were performed using the ASES score, Constant score, SPADI score, DASH score, VAS pain score, patient satisfaction and range of motion. There was a 5-year evaluation of SPADI, ASES, pain, and satisfaction, plus radiographic assessment of glenoid component radiolucent lines and humeral osteolysis.

Results

Seventy-four cases (68.1 ± 7.1 years) had a five-year follow-up and demonstrated active elevation improvement from 91.3° preoperatively to 151.1° (p < 0.001). Further improvement was identified with the ASES from 41.6 to 94.3, the SPADI from 62.9 to 4.3, VAS pain from 5.6 to 0.4 (0–10), and satisfaction levels were at 96%. Sixty-two cases had no glenoid radiolucent lines with a maximum Lazarus score of 2 in one patient. Constant scores, available up to 2 years, improved significantly from 30.3 to 77.9 (p < 0.001). There was one case that required revision for glenoid loosening.

Conclusions

Overall, the 5-year results of this ceramic head prosthesis demonstrated good radiographic and clinical outcomes.

Trial registration

ACTRN12613001183774. Registered: 29 October 2013 - Retrospectively registered.

Australian New Zealand Clinical Trials Registry (ANZCTR).

Intraoperative assembly of anatomical shoulder prosthesis frequently results in malalignment of the modular taper junction

Anatomical shoulder arthroplasties (ASA) may fail because of micromotion at the modular taper junction causing wear due to fretting. Sufficient taper strength can reduce micromotion and potential reasons for failure. However, there are no normative standards for a safe assembly process performed intraoperatively by the surgeon. The purpose of this study is to determine the effect of common intraoperative assembly strategies and to identify critical influencing factors on taper stability. ASA with standard and stemless humeral component in combination with concentric Al₂ O₃ heads and eccentric CoCr28Mo6 alloyed humeral heads were tested. Taper angles and surface roughness were determined. Force magnitudes and impact directions were recorded using a sensorized head impactor and a three-dimensional force measuring platform. Subsequently, the axial pull-off forces were measured and taper engagement areas were macroscopically evaluated. In comparison to standard stem tapers that were impacted with an assembly device, stemless tapers were impacted into the artificial bone with significantly lower forces. Taper strength correlates to maximum impact force and was higher for CoCr28Mo6 heads with a mean pull-off ratio of 0.56 than for Al₂ O₃ heads with 0.37. Interestingly, all tapers showed an asymmetric clamping behavior, due to tilting during impaction. This is caused by the variation of the resulting force vector and further promoted by humeral head eccentricity. Assembly technique markedly influences the force magnitude, impact direction, impulse, and consequently taper strength. The resulting force vector and head eccentricity were identified as potential risk factors for taper malalignment.

A cohort comparison of humeral implant designs in reverse shoulder arthroplasty: does implant design lead to lower rates of complications and revision?

INTRODUCTION

The purpose of this study was to evaluate the outcomes, revisions, and complications between a first-generation cemented modular humeral implant and a second-generation monolithic, primarily uncemented humeral implant in reverse total shoulder arthroplasty with 135° neck-shaft angle and varying degrees of metallic glenosphere offsets.

METHODS

We retrospectively evaluated patients undergoing reverse total shoulder arthroplasty from 2004 to 2014 with a first-generation cemented modular humeral implant (400 patients) or second-generation monolithic humeral stem (231 patients), who had at minimum 2-year clinical and radiographic follow-up.

RESULTS

Both groups of patients had similar improvement of clinical outcomes (American Shoulder and Elbow Surgeons +30 points vs. +34 points, respectively) with improvements in all planes of motion (forward flexion +70° vs. +75°, abduction +61° vs. +71°, external rotation +23° vs. +22°, and internal rotation +1.6 vs. +1.5 level improvement, respectively). The incidence of humeral loosening for the cemented group was 3.6%, whereas in the uncemented group it was 0.4% (P = .01). A total of 28 shoulders treated with the cementing technique (4.0%) and 6 patients treated with the press-fit technique (1.5%) were revised (P = .028). The rate of postoperative acromial fractures within the first year was 3.4% in the cemented group and 1.8% in the uncemented group (P = .177).

CONCLUSIONS

Both the first-generation cemented modular humeral stem implant and the second-generation monolithic humeral stem implant had equivalent clinical outcomes. In addition, with the monolithic stem primarily using press-fit fixation, there was a significant reduction in the incidence of radiographic loosening and the need for revision compared with a cemented stem.

Investigating the International Normalized Ratio Thresholds for Complication in Shoulder Arthroplasty

BACKGROUND

In patients on warfarin anticoagulation therapy, elective shoulder arthroplasty surgeons must carefully balance bleeding and embolic risks. Currently, an international normalized ratio (INR) threshold of 1.5 is supported in the setting of elective surgery. However, no previous study has investigated the optimal preoperative INR target specifically in shoulder arthroplasty. The purpose of this study was to evaluate the association of preoperative INR with rates of transfusion, complication, and readmission/revision surgery in shoulder arthroplasty.

METHODS

Patients who underwent elective shoulder arthroplasty were identified in a national database. The primary outcome of interest was the risk for all-cause complication at 30 days postoperatively. Major and minor complication, revision surgery, and readmission rates were also investigated.

RESULTS

From 2006 to 2016, 1,014 procedures were identified who had undergone elective shoulder arthroplasty with a perioperative INR lab result within 24 hours of surgery. In our cohort, 550 patients (54.2%) were women, with an average age of 71.0 ± 9.8 years. After controlling for confounders, patients with a preoperative INR > 1.5 were 18.9 times as likely to have a major complication as those with a preoperative INR ≤ 1.0 (P = 0.003). Patients with an INR of 1.25 < INR ≤ 1.5 did not have a statistically significant risk of minor or major complication in comparison with those with an INR ≤ 1.0 (P = 0.23, P = 0.67).

DISCUSSION

Although recent hip and knee arthroplasty literature has found that an INR < 1.25 may be an optimal preoperative INR goal, our results did not find an increased risk for bleeding and complication with an INR ≤ 1.5 for shoulder arthroplasty. These results support current guidelines recommending a preoperative INR ≤ 1.5 for shoulder arthroplasty.

3D printing in shoulder surgery

Three-dimensional (3D) printing is a novel modality with the potential to make a huge impact in the surgical field. The aim of this paper is to provide an overview on the current use of 3D printing in shoulder surgery. We have reviewed the use of this new method in 3 fields of shoulder surgery: shoulder arthroplasty, recurrent shoulder instability and orthopedic shoulder traumatology. In shoulder arthroplasty, several authors have shown that the use of the 3D printer improves the positioning of the glenoid component, even if longer clinical follow-up is needed to determine whether the cost of this system rationalizes the potential improved functional outcomes and decreases glenoid revision rates. In the treatment of anterior shoulder instability, the literature agrees on the fact that the use of the 3D printing can: enhance the dept and size of bony lesions, allowing a patient tailored surgical planning and potentially reducing operative times; allow the production of personalized implants to restore substantial bone loss; restore glenohumeral morphology and instability. In orthopedic trauma, the use of 3D printing can be helpful to increase the understanding of fracture patterns, facilitating a more personalized planning, and can be used for resident training and education. We can conclude the current literature regarding the use of 3D printed models in orthopedic surgery agrees finding objective improvements to preoperative planning and to the surgical procedure itself, by shortening the intraoperative time and by the possibility to develop custom-made, patient-specific surgical instruments, and it suggests that there are tangible benefits for its implementation.

[Periprosthetic fractures of the shoulder girdle]

Periprosthetic fractures of the shoulder girdle will increasingly become part of routine clinical practice due to rising numbers of joint replacements and the demographic changes. Diagnostically, the status of the rotator cuff, bed of the implant (stable or loose), type of shoulder arthroplasty as well as exclusion of joint infections are crucial for therapeutic decision-making. Novel imaging tools, such as dual-energy computed tomography provide improved preoperative planning options. The unified classification system describes the fracture location, stability of the prosthesis and quality of the bone. While nonoperative treatment is reserved for patients with severe pre-existing conditions and nondisplaced fractures, the standard treatment of fractures with a stable bed include fixation with cerclage wiring and angular stable plates. Modern implant systems with variable angle screw holes, attachment plates and hinges enable secure fixation around the stem. In cases of a loose stem revision arthroplasty is necessary. There are currently only a limited number of clinical studies with only few patients that analyzed clinical and radiological results. Thus, increased research efforts are indispensable in order to compare treatment options and improve treatment quality.

Hemiarthroplasties: the choice of prosthetic material causes different levels of damage in the articular cartilage

BACKGROUND

Hemiarthroplasty has clear advantages over alternative procedures and is used in 20% of all shoulder joint replacements. Because of cartilage wear, the clinical outcome of hemiarthroplasty is unreliable and controversial. This paper suggests that the optimal choice of prosthetic material may reduce cartilage degeneration and improve the reliability of the procedure. The specific objectives were to assess 3 materials and assess how the severity of arthritis might affect the choice of prosthetic material.

METHODS

A CoCr alloy, an AL₂O₃ ceramic, and a polycarbonate urethane polymer (PCU) were mechanically tested against 5 levels of human osteoarthritic cartilage (from intact to severely arthritic, n = 45). A high friction coefficient, a decrease in Young's modulus, an increase in permeability, a decrease in relaxation time, an increase in surface roughness, and a disrupted appearance of the cartilage after testing were used as measures of cartilage damage. The biomaterial that caused minimal cartilage damage was defined as superior.

RESULTS

The CoCr caused the most damage. This was followed by the AL₂O₃ ceramic, whereas the PCU caused the least amount of damage. Although the degree of arthritis had an effect on the results, it did not change the trend that CoCr performed worst and PCU the best.

DISCUSSION AND CONCLUSION

This study indicates that ceramic implants may be a better choice than metals, and the articulating surface should be as smooth as possible. Although our results indicate that the degree of arthritis should not affect the choice of prosthetic material, this suggestion needs to be further investigated.

A Point-Based Model to Predict Absolute Risk of Revision in Anatomic Shoulder Arthroplasty

Background

Total shoulder arthroplasty (TSA) has demonstrated good long-term survivorship but early implant failure can occur. This study identified factors associated with shoulder arthroplasty revision and constructed a risk score for revision surgery following shoulder arthroplasty.

Methods

A validated algorithm was used to identify all patients who underwent anatomic TSA between 2002 and 2012 using population-based data. Demographic variables included shoulder implant type, age and sex, Charlson comorbidity score, income quintile, diagnosis, and surgeon arthroplasty volume. The associations of covariates with time to revision were measured while treating death as a competing risk and were expressed in the Shoulder Arthroplasty Revision Risk Score (SARRS).

Results

During the study period, 4079 patients underwent TSA. Revision risk decreased in a nonlinear fashion as patients aged and in the absence of osteoarthritis with no influence from surgery type or other covariables. The SARRS ranged from −21 points (5-year revision risk 0.75%) to 30 points (risk 11.4%). Score discrimination was relatively weak 0.55 (95% confidence interval: 0.530.61) but calibration was very good with a test statistic of 5.77 (df = 8, P = .762).

Discussion

The SARRS model accurately predicted the 5-year revision risk in patients undergoing TSA. Validation studies are required before this score can be used clinically to predict revision risk. Further study is needed to determine if the addition of detailed clinical data including functional outcome measures and the severity of glenohumeral arthrosis increases the model’s discrimination.

Shoulder Arthroplasty for Posttraumatic Arthritis Is Associated With Increased Transfusions and Longer Operative Times

Introduction:

Posttraumatic arthritis (PTA) is a common sequela of proximal humerus fractures that is commonly managed with anatomic or reverse total shoulder arthroplasty (TSA). TSA for PTA is more challenging than that performed for primary osteoarthritis and frequently leads to worse patient outcomes. CPT uniformly classifies all cases of primary TSA, irrespective of procedural complexity and resource utilization. This study analyzes intraoperative differences and 30-day outcomes for anatomic and reverse TSA performed in the posttraumatic shoulder.

Methods:

Patients undergoing TSA from 2008 to 2015 were selected from the National Surgical Quality Improvement Program database and stratified according to concurrent procedures and administrative codes indicating posttraumatic diagnoses. Perioperative parameters and 30-day complications were recorded; multivariate analyses were performed to determine whether PTA was a risk factor for poor outcomes.

Results:

A total of 8508 primary and 243 posttraumatic TSAs were identified. Posttraumatic TSA patients were slightly younger ( P = .003), more likely to be female ( P < .001), smokers ( P = .029), and diabetic ( P =  .003). Diagnosis of PTA was an independent risk factor for prolonged operative times ≥160 minutes (≥1 standard deviation above the mean, P =  .003; odds ratio [OR]: 1.718; 95% confidence interval [CI]: 1.204–2.449) and increased bleeding requiring transfusion ( P <  .001; OR: 2.719; 95% CI: 1.607–4.600). Although posttraumatic TSA had a tendency for longer hospital admissions, 30-day readmissions were not significantly different between cohorts.

Conclusions:

Compared with primary osteoarthritis, a preoperative diagnosis of PTA is an independent risk factor for prolonged operative times and postoperative transfusion in anatomic or reverse TSA patients; such patients may be less than optimal candidates for same-day discharges or outpatient shoulder arthroplasty.

Reverse total shoulder arthroplasty and resting radiographic scapular rotation

BACKGROUND

It remains unclear whether changes in scapular rotation influence the surgeon's ability to achieve resting radiographic neutral or inferior baseplate tilt at final follow-up. The purposes of this study were (1) to determine whether reverse total shoulder arthroplasty (RTSA) changes the resting scapular rotation, (2) to determine the association between glenoid inclination with respect to the scapula (β angle) and resting scapular rotation, and (3) to determine the β angle threshold that will most likely lead to resting radiographic neutral or inferior baseplate tilt relative to the thorax.

METHODS

This was a retrospective radiographic study. Patients with adequate-quality standing anteroposterior and Grashey radiographs obtained preoperatively and after primary RTSA at a minimum of 1 year were included. Glenoid inclination (β angle) was measured between the supraspinatus fossa and the glenoid. Resting scapular rotation was measured between the supraspinatus fossa and a vertical line. Baseplate tilt was then calculated as the angle between the glenoid and a vertical line.

RESULTS

The study included 74 patients with a mean follow-up period of 3 years (range, 1-9 years). Scapular rotation changed 2° ± 12° (mean ± standard deviation) into upward rotation (P = .048). No association was found between the β angle and scapular rotation. In 71% of patients with a neutral or inferior baseplate tilt, a postoperative β angle greater than 85° was found.

CONCLUSIONS

Resting radiographic scapular rotation changed 2° into upward rotation with RTSA and was not associated with the β angle. If the β angle is greater than 85°, resting radiographic baseplate tilt will most likely be inferior or neutral.

Anthropometrical study of the human glenoid in a normal Spanish population

OBJECTIVE

To evaluate the size of the glenoid in a southern Spanish population, to compare it with previous results from other populations and determine the size of the implants that are marketed for shoulder arthroplasty.

MATERIAL AND METHODS

Between January 2015 and December 2017, an anthropometrical study of the human glenoid was performed using computed axial tomography scans (CT) of 154 patients over 30 years old. The glenoid dimensions were analysed 3-dimensionally using 2mm interval thicknesses, determining the average height and width of the glenoid. The upper point of the glenoid geometry was determined as the supraglenoid tubercle of the ovoid glenoid surface, where the long head of the biceps tendon is thought to originate. The lower point was then positioned at the furthest point from the upper point on the glenoid contour. Anterior and posterior points were determined such that the 3-dimensional anterior-posterior distance was maximized on the plane perpendicular to the upper-lower axis. Sex differences and correlations between sides and among the respective parameters in the glenohumeral dimensions were also evaluated.

RESULTS

The glenoid had an average height of 28.78mm and width of 20.27mm. The values were significantly different between the men and the women, being greater in the men. The glenoid size is well correlated with the patient's size. Direct correlations exist between the glenoid height and width and the glenoid size and the patient's height. The available metaglenoids currently on the market are no bigger than 25-24mm.

CONCLUSION

In comparison, the southern Spanish population have a glenoid size similar to the Caucasian population, but smaller than that of the American population. The data shown could be useful to improve the design of shoulder prostheses for the southern Spanish population.

Results of total shoulder arthroplasty in patients aged 55 years or younger versus those older than 55 years: an analysis of 1135 patients with over 2 years of follow-up

BACKGROUND

The results of anatomic total shoulder arthroplasty (TSA) in younger patients have not been clearly elucidated. The purpose of this study was to compare early outcomes after TSA in patients aged 55 years or younger versus patients older than 55 years.

METHODS

A total of 1135 patients who were treated with TSA for glenohumeral arthritis and had a mean follow-up period of over 4 years were retrospectively reviewed. Etiologies included osteoarthritis (n = 1044), osteonecrosis (n = 35), inflammatory arthritis (n = 34), and post-traumatic arthritis (n = 22). Validated outcome measures, range of motion, and patient satisfaction were recorded. Preoperative and postoperative metrics were compared, and a multivariate analysis was performed to isolate age from sex, body mass index, previous surgery, and diagnosis as independent factors.

RESULTS

Female patients, patients with a history of surgery, and patients with a diagnosis of osteonecrosis were more likely to undergo TSA when aged 55 years or younger. Both age groups showed similar preoperative range of motion and showed no differences in recorded outcome scores. Postoperatively, patients older than 55 years had slightly greater active abduction (P = .004) and internal rotation (P = .030). A higher percentage of patients older than 55 years rated their outcome as better or much better compared with those aged 55 years or younger (P = .003).

CONCLUSIONS

Female sex, a history of surgery, and a diagnosis of osteonecrosis were associated with undergoing TSA when aged 55 years or younger. Despite similar preoperative function and minor differences in postoperative range of motion and outcome scores, patients aged 55 years or younger reported lower overall satisfaction with their TSA.

Characterization of an anatomic safe zone surrounding the lower subscapular nerve during an open deltopectoral approach

BACKGROUND

Due to anatomic variance in subscapular nerve innervation patterns, it is theorized that the dysfunction of the subscapularis could be the result of iatrogenic denervation during mobilization of the subscapularis while exposing the anterior glenohumeral joint in anterior surgical approaches. The purpose of this study was to describe innervation patterns of the subscapularis and to characterize a safe zone when conducting an anterior surgical approach.

METHODS

The study used 6 human cadaveric shoulder specimens (12 shoulders total). A deltopectoral approach was used to expose the axillary nerve back to the posterior cord of the brachial plexus and reveal the origins of the upper and lower subscapularis nerves. An anatomic safe zone was characterized by measuring distances from both the upper and lower subscapularis nerve insertions with respect to that of the lateral border of the conjoint tendon, the bicipital groove, superior border of the subscapularis, and the axillary nerve (for the lower subscapular nerve only) with the arm in 30° abduction.

RESULTS

The anatomic safe zone of the subscapular nerves medial to the conjoint tendon is less than 32 mm. In relation to the axillary nerve, the safe zone is less than 10 mm inferiorly and 15 mm medially.

CONCLUSIONS

This described safe zone with respect to the lateral border of the conjoint tendon and axillary nerve is aimed to provide guidance to reduce iatrogenic injury of the subscapular nerves during anterior shoulder exposure. Extra care should be undertaken while dissecting past this safe zone to prevent iatrogenic subscapular nerve injury.

The effect of combined loading cycles on the wear of reverse shoulder joint replacements

Wear of polyethylene is a current limitation in the long-term survival of reverse shoulder arthroplasties (RSAs). The purpose of this study was to investigate, for the first time, the influence of a combination of clinically relevant activities of daily living (ADLs) as patterns of motion and loading on the wear of ultra-high molecular-weight polyethylene (UHMWPE) in RSA. This physiological combined cycle, termed "repeated-motion-load", was applied on four new samples of a commercially available reverse shoulder prosthesis for five million cycles using the unique Newcastle Shoulder Wear Simulator. This resulted in a mean wear rate of 12.0 ± 3.9 mm³/million cycles for the UHMWPE components in combination with metallic glenospheres, while the average articulating UHMWPE surface roughness reduced from 692 ± 132 nm Sa to 42 ± 29 nm Sa.

Use of Patient-Specific Instrumentation (PSI) for glenoid component positioning in shoulder arthroplasty. A systematic review and meta-analysis

INTRODUCTION

Total Shoulder Arthroplasty (TSA) anatomical, reverse or both is an increasingly popular procedure but the glenoid component is still a weak element, accounting for 30-50% of mechanical complications and contributing to the revision burden. Component mal-positioning is one of the main aetiological factors in glenoid failure and thus Patient-Specific Instrumentation (PSI) has been introduced in an effort to optimise implant placement. The aim of this systematic literature review and meta-analysis is to compare the success of PSI and Standard Instrumentation (STDI) methods in reproducing pre-operative surgical planning of glenoid component positioning.

MATERIAL AND METHODS

A search (restricted to English language) was conducted in November 2017 on MEDLINE, the Cochrane Library, EMBASE and ClinicalTrials.gov. Using the search terms "Patient-Specific Instrumentation (PSI)", "custom guide", "shoulder", "glenoid" and "arthroplasty", 42 studies were identified. The main exclusion criteria were: no CT-scan analysis results; studies done on plastic bone; and use of a reusable or generic guide. Eligible studies evaluated final deviations from the planning for version, inclination, entry point and rotation. Reviewers worked independently to extract data and assess the risk of bias on the same studies.

RESULTS

The final analysis included 12 studies, comprising 227 participants (seven studies on 103 humans and five studies on 124 cadaveric specimens). Heterogeneity was moderate or high for all parameters. Deviations from the pre-operative planning for version (p<0.01), inclination (p<0.01) and entry point (p = 0.02) were significantly lower with the PSI than with the STDI, but not for rotation (p = 0.49). Accuracy (deviation from planning) with PSI was about 1.88° to 4.96°, depending on the parameter. The number of component outliers (>10° of deviation or 4mm) were significantly higher with STDI than with PSI (68.6% vs 15.3% (p = 0.01)).

CONCLUSION

This review supports the idea that PSI enhances glenoid component positioning, especially a decrease in the number of outliers. However, the findings are not definitive and further validation is required. It should be noted that no randomised clinical studies are available to confirm long-term outcomes.

Differences in total blood loss and transfusion rate between different indications for shoulder arthroplasty

PURPOSE

In this study, the total blood loss, transfusion rate and number of transfused blood units in patients with different indications for shoulder arthroplasty: primary, fracture and secondary were compared. Risk factors for bleeding and transfusion were analysed.

METHODS

Medical records and the database of the institution's blood bank from 527 patients that received shoulder arthroplasty were analysed retrospectively. This study included 419 patients that were divided in three different groups: primary (n = 278), fracture (n = 110) and secondary (following prior osteosynthesis; n = 31) shoulder arthroplasty. The demographic and clinical data were collected. The total blood loss (TBL) was calculated and transfusions recorded.

RESULTS

The transfusion rate and mean amount of transfused blood units (BU) were higher in fracture (32.7% and 0.69BU, p < 0.01) and secondary arthroplasty (35.5% and 0.97BU, p < 0.01) than in primary arthroplasty (12.6% and 0.28BU). The overall transfusion rate was 19.6% at a mean TBL of 370 ml. However, patients with primary arthroplasty experienced significantly higher total blood loss than those after fracture arthroplasty (p < 0.01). Longer surgery time and male sex are significant risk factors for elevated blood loss. The pre-operative use of vitamin K antagonist, cemented arthroplasty, high BMI, coronary heart disease and ASA score > 2 are relevant risk factors for blood transfusion.

CONCLUSION

The most important susceptible factor that affects the TBL is the surgery time. Transfusion rates are higher in patients with fracture arthroplasty than after primary arthroplasty.

Reverse Shoulder Arthroplasty With Proximal Humeral Replacement for the Management of Massive Proximal Humeral Bone Loss

Background

Substantial proximal humeral bone loss may compromise reverse shoulder arthroplasty secondary to limited implant support, insufficient soft tissue tension due to shortening, lack of attachment sites for the posterosuperior cuff when present, and lack of lateral offset of the deltoid. In these circumstances, use of a proximal humeral replacement may be considered.

Patients/Methods

Between 2012 and 2014, 34 consecutive reverse shoulder arthroplasties were performed using a proximal humeral replacement system. The indications were failed shoulder arthroplasty (15), oncology reconstruction (9), humeral malunion/nonunion (7), prior resection arthroplasty (2), and intraoperative fracture (1). All patients were included in the survival analysis. Twenty-two patients with minimum 2-year follow-up were included in analysis of clinical results.

Results

Among the cohort of 34 patients, there were 8 additional reoperations: humeral loosening (3), periprosthetic fracture (2), irrigation and debridement (2), and glenoid loosening (1). Humeral component loosening occurred exclusively in patients undergoing revision shoulder arthroplasty. The 4 patients had an average 3.75 prior procedures before the proximal humeral replacement. Two of the revisions were from cemented to uncemented stems. Among the 23 patients with minimum 2-year follow-up, there was significant improvement in pain scores (4.1 vs 0.6), forward elevation (31 vs 109) degrees, and 81% were satisfied.

Conclusion

Use of a proximal humeral replacement when performing a reverse shoulder arthroplasty in the complex setting of substantial proximal humerus bone loss provides good clinical results and a particularly low dislocation rate. However, the rate of loosening of the humeral component in the revision setting suggests that proximal humeral replacement components should be cemented when revising a previously cemented stem.

IRB

16-006966.

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.

International variation in shoulder arthroplasty

Background and purpose - The number of shoulder registries increases. We assessed international trends in use of shoulder arthroplasty, and described the current state of procedure selection and outcome presentation as documented in national and regional joint registries. Methods - Published reports from 9 population-based shoulder arthroplasty registries (country/region: Norway, Sweden, New Zealand, Denmark, California, Australia, Emilia-Romagna, Germany, and United Kingdom) were analyzed. Data were extracted on age, sex, disease indication, type of surgical procedure, surgical volume, and outcomes. Results - Shoulder arthroplasty incidence rate in 2012 was 20 procedures/10⁵ population with a 6-fold variation between the highest (Germany) and lowest (United Kingdom) country. The annual incidence rate increased 2.8-fold in the past decade. Within the indications osteoarthritis, fracture, and cuff-tear arthropathy variations in procedure choice between registries were large. Outcomes evaluation focused on revision in all registries, but different measures and strata were used. Only Australia provided revision rates for prosthesis brands stratified by both indication and procedure. Finally, in 2 registries with available data surgeons performed on average 10-11 procedures yearly. Interpretation - Annual incidence rates of shoulder arthroplasty have almost tripled over the past decade. There is wide variation in procedure selection for the major indications, a low average surgeon volume, a substantial number of brands with small annual volume, and large variation in outcome presentation. The internationally increasing registry activity is an excellent basis for improving the so far weak evidence in shoulder arthroplasty.

Management of the subscapularis tendon during total shoulder arthroplasty

Use of total shoulder arthroplasty has significantly increased during the past decade. For anatomic total shoulder arthroplasty, controversy exists regarding the best technique for detachment and repair of the subscapularis tendon. Options include tendon tenotomy, peel, lesser tuberosity osteotomy, and even subscapularis-sparing techniques. Inadequate healing of the subscapularis tendon can lead to postoperative pain, weakness, and instability. This review discusses the subscapularis pathoanatomy, different techniques for releasing and repairing the tendon, and reports biomechanical and clinical outcomes for each technique after total shoulder arthroplasty.

Long-Term Outcomes of Reverse Total Shoulder Arthroplasty: A Follow-up of a Previous Study

BACKGROUND

Despite the increasing numbers of reverse total shoulder arthroplasty (RTSA) procedures, the long-term results have been rarely reported. We previously reported early outcomes of a cohort of patients treated with a Grammont-style RTSA. The purpose of this study was to evaluate the outcomes after a minimum of 10 years, and to document prosthetic survival and complications.

METHODS

Clinical outcome assessment was based on the absolute and relative Constant scores and the active range of motion. Radiographic evaluations of scapular notching, tuberosity osteolysis, and periprosthetic radiolucent lines were done as well. Complications and revisions were compiled, and a Kaplan-Meier survival analysis was performed.

RESULTS

The original report included the outcomes for 186 patients (191 RTSAs) who had been followed for a mean of 40 months. In the present study, in which the mean duration of follow-up was 150 months, follow-up clinical evaluations were available for 84 patients (87 prostheses) and radiographic assessments were available for 64 patients (67 prostheses). Seventy-seven patients (79 prostheses) had died before the 10-year follow-up, and 17 patients (17 prostheses) had been lost to follow-up. The mean absolute and relative Constant scores (and standard deviations) were 55 ± 16 points and 86 ± 26 points, respectively, with both having decreased significantly compared with the scores at the medium-term follow-up evaluation (at a minimum of 2 years) (p < 0.001 and p = 0.025, respectively). Forty-nine shoulders (73%) exhibited scapular notching. Forty-seven complications (29%) were recorded, with 10 cases (10%) occurring after 2 years. Sixteen (12%) of the original patients underwent revision surgery. The 10-year overall prosthetic survival rate using revision as the end point was 93%.

CONCLUSIONS

Despite a high arthroplasty survival rate and good long-term clinical results, RTSA outcomes showed deterioration when compared with medium-term results. The cause of this decrease is probably related to patient aging coupled with bone erosion and/or deltoid impairment over time.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

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

PURPOSE

The purpose of the study was to evaluate the position of the subscapular nerves relative to surgical landmarks during exposure and to analyze the pattern of innervation of the subscapularis to avoid injury during anterior shoulder surgery.

METHODS

20 embalmed human cadaveric shoulder specimens were used in the study. The muscular insertions of the subscapular nerves were marked and their closest branches to the musculotendinous junction and the coracoid process were measured in horizontal and vertical distances. In addition, the innervation pattern of each specimen was documented.

RESULTS

14/20 specimens showed an innervation of the subscapularis with an upper, middle and lower subscapular nerve branch. Even though the nerve branches were in average more than 2 cm medial to the musculotendinous junction, minimal distances of 1.1-1.3 cm were found. The mean vertical distance as measured from the medial base of the coracoid to the nerve innervation point into the muscle was 0.7 cm for the upper nerve branch, 2.2 cm for the middle nerve branch and 4.4 cm for the lower nerve branch.

CONCLUSIONS

The subscapularis has a variable nerve supply, which increases the risk of muscle denervation during open shoulder surgery. Dissection or release should be avoided at the anterior aspect of the subscapularis muscle more than 1 cm medial to the musculotendinous junction. In approaches with a horizontal incision of the subscapularis, splitting should be performed at a vertical distance of 3.2-3.6 cm to the coracoid base to avoid iatrogenic subscapular nerve injuries.

Is there any influence of humeral component retroversion on range of motion and clinical outcome in reverse shoulder arthroplasty? A clinical study

PURPOSE

Reverse shoulder arthroplasty becomes more widely used as treatment for patients with complex cuff arthropathy. Theoretically, a higher retroversion of the humeral component leads to an increase in external rotation ROM and a decrease in internal rotation ROM. There is no consensus in optimal retroversion orientation. We retrospectively describe the effect of retroversion of the humeral component. We hypothesize that 20° humeral retroversion improves postoperative ROM, strength or clinical outcome scores compared to neutral retroversion.

METHODS

A retrospective clinical study is performed. An Aequalis reverse shoulder prosthesis was placed in 65 shoulders from 58 patients with a mean age of 73.8 years (95% CI 72.0-75.6). Between October 2006 and May 2012, the humeral component was placed in neutral retroversion in 36 shoulders (55%). From June 2012 to June 2014, it was placed in 20° retroversion in 29 shoulders (45%). After a mean follow-up of 36 months with a minimum of 12 months, patients were invited for a study visit. ROM, strength, Constant-Murley and Oxford Scores were measured.

RESULTS

ROM, strength and Constant-Murley and Oxford Scores did not differ significantly between both groups.

CONCLUSIONS

With the Aequalis prosthesis, no significant effect of 0° or 20° retroversion on external and internal rotation ROM, strength or functional outcome scores was found.

Fretting and Corrosion in Modular Shoulder Arthroplasty: A Retrieval Analysis

Tribocorrosion in taper junctions of retrieved anatomic shoulder arthroplasty implants was evaluated. A comparison of the tribocorrosion between cobalt-chromium and titanium alloy stems was conducted and the observations were correlated with the individual's clinical data. Adverse effects caused by metal debris and subsequent elevated serum metal ion levels are frequently reported in total hip arthroplasty. In total shoulder arthroplasty, to date only a small number of retrieval analyses are available and even fewer address the issue of tribocorrosion at the taper junctions. A total of 36 retrieved hemiarthroplasties and total shoulder arthroplasties were assessed using the modified Goldberg score. The prevalence of fretting and corrosion was confirmed in this cohort. Titanium stems seem to be more susceptible to damage caused by tribocorrosion than cobalt-chromium stems. Furthermore, stemless designs offered less tribocorrosion at the taper junction than stemmed designs. A weak correlation between time to revision and increased levels of tribocorrosion was seen. Whether or not tribocorrosion can lead to adverse clinical reactions and causes failure of shoulder arthroplasties remains to be examined.