The August 2024 Shoulder & Elbow Roundup³⁶⁰ looks at: Comparing augmented and nonaugmented locking-plate fixation for proximal humeral fractures in the elderly; Elevated five-year mortality following shoulder arthroplasty for fracture; Total intravenous anaesthesia with propofol reduces discharge times compared with inhaled general anaesthesia in shoulder arthroscopy: a randomized controlled trial; The influence of obesity on outcomes following arthroscopic rotator cuff repair; Humeral component version has no effect on outcomes following reverse total shoulder arthroplasty: a prospective, double-blinded, randomized controlled trial; What is a meaningful improvement after total shoulder arthroplasty by implant type, preoperative diagnosis, and sex?; The safety of corticosteroid injection prior to shoulder arthroplasty: a systematic review; Mortality and subsequent fractures of patients with olecranon fractures compared to other upper limb osteoporotic fractures.

Aims. Shoulder arthroplasty is effective in the management of end-stage glenohumeral joint arthritis. However, it is major surgery and patients must balance multiple factors when considering the procedure. An understanding of patients’ decision-making processes may facilitate greater support of those considering shoulder arthroplasty and inform the outcomes of future research. Methods. Participants were recruited from waiting lists of three consultant upper limb surgeons across two NHS hospitals. Semi-structured interviews were conducted with 12 participants who were awaiting elective shoulder arthroplasty. Transcribed interviews were analyzed using a grounded theory approach. Systematic coding was performed; initial codes were categorized and further developed into summary narratives through a process of discussion and refinement. Data collection and analyses continued until thematic saturation was reached. Results. Two overall categories emerged: the motivations to consider surgery, and the information participants used to inform their decision-making. Motivations were, broadly, the relief of pain and the opportunity to get on with life and regain independence. When participants’ symptoms and restrictions prevented them enjoying life to a sufficient extent, this provided the motivation to proceed with surgery. Younger participants tended to focus on maintaining employment and recreational activities, and older patients were eager to make the most of their remaining lifetime. Participants gathered information from a range of sources and were keen to optimize their recovery where possible. An important factor for participants was whether they trusted their surgeon and were prepared to delegate responsibility for elements of their care. Conclusion. Relief of pain and the opportunity to get on with life were the primary reasons to undergo shoulder arthroplasty. Participants highlighted the importance of the patient-surgeon relationship and the need for accurate information in an accessible format which is relevant to people of different ages and functional demands. Cite this article: Bone Jt Open 2024;5(7):543–549

Aims

Both anatomical and reverse total shoulder arthroplasty (aTSA and rTSA) provide functional improvements. A reported benefit of aTSA is better range of motion (ROM). However, it is not clear which procedure provides better outcomes in patients with limited foward elevation (FE). The aim of this study was to compare the outcome of aTSA and rTSA in patients with glenohumeral osteoarthritis (OA), an intact rotator cuff, and limited FE.

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The aim of this study was to longitudinally compare the clinical and radiological outcomes of anatomical total shoulder arthroplasty (aTSA) up to long-term follow-up, when using cemented keel, cemented peg, and hybrid cage peg glenoid components and the same humeral system.

Aims

The open Latarjet procedure is a widely used treatment for recurrent anterior instability of the shoulder. Although satisfactory outcomes are reported, factors which influence a patient’s experience are poorly quantified. The aim of this study was to evaluate the effect of a range of demographic factors and measures of the severity of instability on patient-reported outcome measures in patients who underwent an open Latarjet procedure at a minimum follow-up of two years.

Knowledge of the premorbid glenoid shape and the morphological changes the bone undergoes in patients with glenohumeral arthritis can improve surgical outcomes in total and reverse shoulder arthroplasty. Several studies have previously used scapular statistical shape models (SSMs) to predict premorbid glenoid shape and evaluate glenoid erosion properties. However, current literature suggests no studies have used scapular SSMs to examine the changes in glenoid surface area in patients with glenohumeral arthritis. Therefore, the purpose of this study was to compare the glenoid articular surface area between pathologic glenoid cavities from patients with glenohumeral arthritis and their predicted premorbid shape using a scapular SSM. Furthermore, this study compared pathologic glenoid surface area with that from virtually eroded glenoid models created without influence from internal bone remodelling activity and osteophyte formation. It was hypothesized that the pathologic glenoid cavities would exhibit the greatest glenoid surface area despite the eroded nature of the glenoid and the medialization, which in a vault shape, should logically result in less surface area. Computer tomography (CT) scans from 20 patients exhibiting type A2 glenoid erosion according to the Walch classification [Walch et al., 1999] were obtained. A scapular SSM was used to predict the premorbid glenoid shape for each scapula. The scapula and humerus from each patient were automatically segmented and exported as 3D object files along with the scapular SSM from a pre-operative planning software. Each scapula and a copy of its corresponding SSM were aligned using the coracoid, lateral edge of the acromion, inferior glenoid tubercule, scapular notch, and the trigonum spinae. Points were then digitized on both the pathologic humeral and glenoid surfaces and were used in an iterative closest point (ICP) algorithm in MATLAB (MathWorks, Natick, MA, USA) to align the humerus with the glenoid surface. A Boolean subtraction was then performed between the scapular SSM and the humerus to create a virtual erosion in the scapular SSM that matched the erosion orientation of the pathologic glenoid. This led to the development of three distinct glenoid models for each patient: premorbid, pathologic, and virtually eroded (Fig. 1). The glenoid surface area from each model was then determined using 3-Matic (Materialise, Leuven, Belgium). Figure 1. (A) Premorbid glenoid model, (B) pathologic glenoid model, and (C) virtually eroded glenoid model. The average glenoid surface area for the pathologic scapular models was 70% greater compared to the premorbid glenoid models (P < 0 .001). Furthermore, the surface area of the virtual glenoid erosions was 6.4% lower on average compared to the premorbid glenoid surface area (P=0.361). The larger surface area values observed in the pathologic glenoid cavities suggests that sufficient bone remodelling exists at the periphery of the glenoid bone in patients exhibiting A2 type glenohumeral arthritis. This is further supported by the large difference in glenoid surface area between the pathologic and virtually eroded glenoid cavities as the virtually eroded models only considered humeral anatomy when creating the erosion. For any figures or tables, please contact the authors directly

Patients receiving reverse total shoulder arthroplasty (RTSA) often have osseous erosions because of glenohumeral arthritis, leading to increased surgical complexity. Glenoid implant fixation is a primary predictor of the success of RTSA and affects micromotion at the bone-implant interface. Augmented implants which incorporate specific geometry to address superior erosion are currently available, but the clinical outcomes of these implants are still considered short-term. The objective of this study was to investigate micromotion at the glenoid-baseplate interface for a standard, 3 mm and 6 mm lateralized baseplates, half-wedge, and full-wedge baseplates. It was hypothesized that the mechanism of load distribution from the baseplate to the glenoid will differ between implants, and these varying mechanisms will affect overall baseplate micromotion. Clinical CT scans of seven shoulders (mean age 69 years, 10°-19° glenoid inclinations) that were classified as having E2-type glenoid erosions were used to generate 3D scapula models using MIMICS image processing software (Materialise, Belgium) with a 0.75 mm mesh size. Each scapula was then repeatedly virtually reconstructed with the five implant types (standard,3mm,6mm lateralized, and half/full wedge; Fig.1) positioned in neutral version and inclination with full backside contact. The reconstructed scapulae were then imported into ABAQUS (SIMULIA, U.S.) finite element software and loads were applied simulating 15°,30°,45°,60°,75°, and 90° of abduction based on published instrumented in-vivo implant data. The micromotion normal and tangential to the bone surface, and effective load transfer area were recorded for each implant and abduction angle. A repeated measures ANOVA was used to perform statistical analysis. Maximum normal micromotion was found to be significantly less when using the standard baseplate (5±4 μm), as opposed to the full-wedge (16±7 μm, p=0.004), 3 mm lateralized (10±6 μm, p=0.017), and 6 mm lateralized (16±8 μm, p=0.007) baseplates (Fig.2). The half-wedge baseplate (11±7 μm) also produced significantly less micromotion than the full-wedge (p=0.003), and the 3 mm lateralized produced less micromotion than the full wedge (p=0.026) and 6 mm lateralized (p=0.003). Similarly, maximum tangential micromotion was found to be significantly less when using the standard baseplate (7±4 μm), as opposed to the half-wedge (12±5 μm, p=0.014), 3 mm lateralized (10±5 μm, p=0.003), and 6 mm lateralized (13±6 μm, p=0.003) baseplates (Fig.2). The full wedge (11±3 μm), half-wedge, and 3 mm lateralized baseplate also produced significantly less micromotion than the 6 mm lateralized (p=0.027, p=012, p=0.02, respectively). Both normal and tangential micromotion were highest at the 30° and 45° abduction angles (Fig.2). The effective load transfer area (ELTA) was lowest for the full wedge, followed by the half wedge, 6mm, 3mm, and standard baseplates (Fig.3) and increased with abduction angle. Glenoid baseplates with reduced lateralization and flat backside geometries resulted in the best outcomes with regards to normal and tangential micromotion. However, these types of implants are not always feasible due to the required amount of bone removal, and medialization of the bone-implant interface. Future work should study the acceptable levels of bone removal for patients with E-type glenoid erosion and the corresponding best implant selections for such cases. For any figures or tables, please contact the authors directly

Shoulder arthroplasty is effective at restoring function and relieving pain in patients suffering from glenohumeral arthritis; however, cortex thinning has been significantly associated with larger press-fit stems (fill ratio = 0.57 vs 0.48; P = 0.013)1. Additionally, excessively stiff implant-bone constructs are considered undesirable, as high initial stiffness of rigid fracture fixation implants has been related to premature loosening and an ultimate failure of the implant-bone interface2. Consequently, one objective which has driven the evolution of humeral stem design has been the reduction of stress-shielding induced bone resorption; this in-part has led to the introduction of short stems, which rely on metaphyseal fixation. However, the selection of short stem diametral (i.e., thickness) sizing remains subjective, and its impact on the resulting stem-bone construct stiffness has yet to be quantified. Eight paired cadaveric humeri (age = 75±15 years) were reconstructed with surgeon selected ‘standard’ sized and 2mm ‘oversized’ short-stemmed implants. Standard stem sizing was based on a haptic assessment of stem and broach stability per typical surgical practice. Anteroposterior radiographs were taken, and the metaphyseal and diaphyseal fill ratios were quantified. Each humerus was then potted in polymethyl methacrylate bone cement and subjected to 2000 cycles of compressive loading representing 90º forward flexion to simulate postoperative seating. Following this, a custom 3D printed metal implant adapter was affixed to the stem, which allowed for compressive loading in-line with the stem axis (Fig.1). Each stem was then forced to subside by 5mm at a rate of 1mm/min, from which the compressive stiffness of the stem-bone construct was assessed. The bone-implant construct stiffness was quantified as the slope of the linear portion of the resulting force-displacement curves. The metaphyseal and diaphyseal fill ratios were 0.50±0.10 and 0.45±0.07 for the standard sized stems and 0.50±0.06 and 0.52±0.06 for the oversized stems, respectively. Neither was found to correlate significantly with the stem-bone construct stiffness measure (metaphysis: P = 0.259, diaphysis: P = 0.529); however, the diaphyseal fill ratio was significantly different between standard and oversized stems (P < 0.001, Power = 1.0). Increasing the stem size by 2mm had a significant impact on the stiffness of the stem-bone construct (P = 0.003, Power = 0.971; Fig.2). Stem oversizing yielded a construct stiffness of −741±243N/mm; more than double that of the standard stems, which was −334±120N/mm. The fill ratios reported in the present investigation match well with those of a finite element assessment of oversizing short humeral stems3. This work complements that investigation's conclusion, that small reductions in diaphyseal fill ratio may reduce the likelihood of stress shielding, by also demonstrating that oversizing stems by 2mm dramatically increases the stiffness of the resulting implant-bone construct, as stiffer implants have been associated with decreased bone stimulus4 and premature loosening2. The present findings suggest that even a small, 2mm, variation in the thickness of short stem humeral components can have a marked influence on the resulting stiffness of the implant-bone construct. This highlights the need for more objective intraoperative methods for selecting stem size to provide guidelines for appropriate diametral sizing. For any figures or tables, please contact the authors directly

Aims

This study compared patients who underwent arthroscopic repair of large to massive rotator cuff tears (LMRCTs) with isolated incomplete repair of the tear and patients with incomplete repair with biceps tendon augmentation. We aimed to evaluate the additional benefit on clinical outcomes and the capacity to lower the re-tear rate.

Aims. Corticosteroid injections are often used to manage glenohumeral arthritis in patients who may be candidates for future total shoulder arthroplasty (TSA) or reverse shoulder arthroplasty (rTSA). In the conservative management of these patients, corticosteroid injections are often provided for symptomatic relief. The purpose of this study was to determine if the timing of corticosteroid injections prior to TSA or rTSA is associated with changes in rates of revision and periprosthetic joint infection (PJI) following these procedures. Methods. Data were collected from a national insurance database from January 2006 to December 2017. Patients who underwent shoulder corticosteroid injection within one year prior to ipsilateral TSA or rTSA were identified and stratified into the following cohorts: < three months, three to six months, six to nine months, and nine to 12 months from time of corticosteroid injection to TSA or rTSA. A control cohort with no corticosteroid injection within one year prior to TSA or rTSA was used for comparison. Univariate and multivariate analyses were conducted to determine the association between specific time intervals and outcomes. Results. In total, 4,252 patients were included in this study. Among those, 1,632 patients (38.4%) received corticosteroid injection(s) within one year prior to TSA or rTSA and 2,620 patients (61.6%) did not. On multivariate analysis, patients who received corticosteroid injection < three months prior to TSA or rTSA were at significantly increased risk for revision (odds ratio (OR) 2.61 (95% confidence interval (CI) 1.77 to 3.28); p < 0.001) when compared with the control cohort. However, there was no significant increase in revision risk for all other timing interval cohorts. Notably, Charlson Comorbidity Index ≥ 3 was a significant independent risk factor for all-cause revision (OR 4.00 (95% CI 1.40 to 8.92); p = 0.036). Conclusion. There is a time-dependent relationship between the preoperative timing of corticosteroid injection and the incidence of all-cause revision surgery following TSA or rTSA. This analysis suggests that an interval of at least three months should be maintained between corticosteroid injection and TSA or rTSA to minimize risks of subsequent revision surgery. Cite this article: Bone Joint J 2022;104-B(5):620–626

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The aim of this study is to provide a detailed description of cases combining bridging patch repair with artificial ligament “internal brace” reinforcement to treat irreparable massive rotator cuff tears, and report the preliminary results.

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The aim of this study was to describe a quantitative 3D CT method to measure rotator cuff muscle volume, atrophy, and balance in healthy controls and in three pathological shoulder cohorts.

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

Total shoulder arthroplasty (TSA) is an effective treatment for end-stage glenohumeral arthritis. The use of high modulus uncemented stems causes stress shielding and induces bone resorption of up to 63% of patients following TSA. Shorter length stems with smaller overall dimensions have been studied to reduce stress shielding, however the effect of humeral short stem varus-valgus positioning on bone stress is not known. The purpose of this study was to quantify the effect of humeral short stem varus-valgus angulation on bone stresses after TSA. Three dimensional models of eight male cadaveric humeri (mean±SD age:68±6 years) were created from computed tomography data using MIMICS (Materialise, Belgium). Separate cortical and trabecular bone sections were created, and the resulting bone models were virtually reconstructed three times by an orthopaedic surgeon using an optimally sized short stem humeral implant (Exactech Preserve) that was placed directly in the center of the humeral canal (STD), as well as rotated varus (VAR) or valgus (VAL) until it was contacting the cortex. Bone was meshed using a custom technique which produced identical bone meshes permitting the direct element-to-element comparison of bone stress. Cortical bone was assigned an elastic modulus of 20 GPa and a Poisson's ratio of 0.3. Trabecular bone was assigned varying stiffness based on CT attenuation. A joint reaction force was then applied to the intact and reconstructed humeri representing 45˚ and 75˚ of abduction. Changes in bone stress, as well as the expected bone response based on change in strain energy density was then compared between the intact and reconstructed states for all implant positions. Both varus and valgus positioning of the humeral stem altered both the cortical and trabecular bone stresses from the intact states. Valgus positioning had the greatest negative effect in the lateral quadrant for both cortical and trabecular bone, producing greater stress shielding than both the standard and varus positioned implant. Overall, the varus and standard positions produced values that most closely mimicked the intact state. Surprisingly, valgus positioning produced large amounts of stress shielding in the lateral cortex at both 45˚ and 75˚ of abduction but resulted in a slight decrease in stress shielding in the medial quadrant directly beneath the humeral resection plane. This might have been a result of direct contact between the distal end of the implant and the medial cortex under loading which permitted load transfer, and therefore load-reduction of the lateral cortex during abduction. Conversely, when the implant was placed in the varus angulation, noticeable departures in stress shielding and changes in bones stress were not observed when compared to the optimal STD position. Interestingly, for the varus positioned implant, the deflection of the humerus under load eliminated the distal stem-cortex contact, hence preventing distal load transfer thus precluding the transfer of load

Introduction. Total shoulder arthroplasty (TSA) is an effective treatment to restore shoulder function and alleviate pain in the case of glenohumeral arthritis [1]. Stress shielding, which occurs when bone stress is reduced due to the replacement of bone with a stiffer metallic implant, causes bone resorption of up to 9% of the humeral cortical thickness following TSA [2]. Shorter length stems and smaller overall geometries may reduce stress shielding [3], however the effect of humeral head backside contact with the resection plane has not yet been fully investigated on bone stress. Therefore, the purpose of this study was to quantify the effect of humeral head contact conditions on bone stresses following TSA. Methods. 3D models of eight male left cadaveric humeri (68±6 years) were generated from CT data using MIMICS. These were then virtually prepared for reconstruction by an orthopaedic surgeon to accept a short-stem humeral implant (Exactech Equinoxe® Preserve) that was optimally sized and placed centrally in the humeral canal. The humeral head was positioned in the inferior-medial position such that contact was achieved on the medial cortex, and no contact existed on the lateral cortex. Three different humeral head backside contact conditions were investigated (Figure 1); full backside contact (FULL), contact with only the inferior-medial half of the resection (INF), and contact with only the superior-lateral half of the resection (SUP). Cortical bone was assigned an elastic modulus of 20 GPa and a Poisson's ratio of 0.3. Trabecular bone was assigned varying stiffness based on CT attenuation [4]. A joint reaction force was then applied representing 45˚ and 75˚ of abduction [5]. Changes in bone stress, as well as the expected bone response based on change in strain energy density [6] was then compared between the intact and reconstructed states. Results. For cortical bone, the full backside contact altered bone stress by 28.9±5.5% compared to intact, which was significantly less than the superior (37.0±3.9%, P=0.022) and inferior (53.4±3.9%, P<0.001) backside contact conditions. Similar trends were observed for changes in trabecular bone stress relative to the intact state, where the full backside contact altered bone stress by 86.3±27.9% compared to intact, compared to the superior and inferior contact conditions, which altered bone stress by 115.2±45.0% (P=0.309) and 197.4±80.2% (P=0.024), respectively. In terms of expected bone response, both the superior and inferior contact resulted in an increase in bone volume with resorbing potential compared to the full contact (Figure 2). Discussion and Conclusions. The results of this study show that full humeral head backside contact with the humeral resection plane is preferable for short stem humeral TSA implants with the head in the inferior-medial position. As expected, the superior contact typically increased resorption potential in the medial quadrant due to the lack of load transfer, however interestingly the inferior contact increased resorption potential in both the lateral and medial quadrants. Analysis of implant micromotion showed that medial liftoff of the implant occurred, which resulted in a lack of load transfer in the most medial aspect of the resection plane. For any figures or tables, please contact the authors directly

Background. Rotator cuff atrophy evaluated with computed tomography scans has been associated with asymmetric glenoid wear and humeral head subluxation in glenohumeral arthritis. Magnetic resonance imaging has increased sensitivity for identifying rotator cuff pathology and has not been used to investigate this relationship. The purpose of this study was to use MRI to assess the association of rotator cuff muscle atrophy and glenoid morphology in primary glenohumeral arthritis. Methods. 132 shoulders from 129 patients with primary GHOA were retrospectively reviewed and basic demographic information was collected. All patients had MRIs that included appropriate orthogonal imaging to assess glenoid morphology and rotator cuff pathology and were reviewed by two senior surgeons. All patients had intact rotator cuff tendons. Glenoid morphology was assigned using the modified-Walch classification system (types A1, A2, B1, B2, B3, C, and D) and rotator cuff fatty infiltration was assigned using Goutallier scores. Results. 46 (35%) of the shoulders had posterior wear patterns (23 type B2s, 23 type B3s). Both the infraspinatus and teres minor independently had significantly more fatty infiltration in B2 and B3 type glenoids compared to type A glenoids (p<0.001). There was a greater imbalance in posterior rotator cuff muscle fatty atrophy in B2 and B3 type glenoids compared to type A glenoids (p<0.001). However, there was no difference in axial plane imbalance between B2 and B3 glenoids (p=1.00). There was increased amount fatty infiltration of the infraspinatus among B2 and B3-type glenoids compared to type A glenoids on multivariate analysis controlling for age and gender (p<0.001). Conclusions. These results identify significant axial plane rotator cuff muscle imbalances in B2 and B3-type glenoids compared to concentrically worn glenoids, favoring a relative increase in fatty infiltration of the infraspinatus and teres minor compared to the subscapularis in glenoids with patterns of posterior wear. For any figures or tables, please contact authors directly

Aims

The aim of this study was to use national registry database information to estimate cumulative rates and relative risk of revision due to infection after reverse shoulder arthroplasty.

The treatment of proximal humerus fractures remains controversial. The literature is full of articles and commentary supporting one method over another. Options include open reduction and internal fixation, hemiarthroplasty, and reverse shoulder arthroplasty. Treatment options in an active 65-year-old are exceptionally controversial given the fact that people in this middle-aged group still wished to remain active and athletic in many circumstances. A hemiarthroplasty offers the advantage of a greater range of motion, however, this has a high incidence of tuberosity malunion or nonunion and this is a very common reason for revision of that hemiarthroplasty for fracture to a reverse shoulder replacement. One recent study showed a 73% incidence of tuberosity malunion or nonunion in shoulders that had a revised hemiarthroplasty to a reverse shoulder replacement. Progressive glenoid wear and erosion is also a risk after a hemiarthroplasty in the younger patient, especially someone who is young and active. In addition, studies show shorter operative time in hemiarthroplasty. The range of motion is highly dependent on proper tuberosity healing and this is often one of the most challenging aspects of the surgical procedure as well as the healing process. A reverse shoulder replacement in general has less range of motion compared to a hemiarthroplasty with anatomically healed tuberosities, however, the revision rate is lower compared to a hemiarthroplasty. (This is likely related to few were options for revision). The results after a reverse shoulder replacement may not be as dependent on tuberosity healing, however, importantly the tuberosities do need to be repaired and the results are significantly better if there is healing of the greater tuberosity, giving some infraspinatus and/or teres minor function to the shoulder. Complete lack of tuberosity healing forces the shoulder into obligate internal rotation with attempted elevation and this can be functionally disabling. Academic discussion is beginning surrounding the use of a reverse shoulder replacement in the setting of glenohumeral joint arthritis in a primary setting as it is believed that the glenosphere and baseplate may have greater longevity than a polyethylene glenoid. Along with this discussion, we will likely see greater application of the use of a reverse shoulder replacement in the setting of fracture for younger patients. In general, open reduction internal fixation should still remain the treatment of choice in the setting of a fracture that can be fixed. However, a strong argument can be made that if an arthroplasty is necessary, a reverse shoulder replacement is the implant of choice

Aims

Few studies have compared survivorship of total shoulder arthroplasty (TSA) with hemiarthroplasty (HA). This observational study compared survivorship of TSA with HA while controlling for important covariables and accounting for death as a competing risk.