Impaction autografting: bone-preserving, secure fixation of a standard humeral component

Cementless Reverse Shoulder Arthroplasty Technique to Maximize Press-Fit Fixation with Humeral Matchstick Bone Grafts

Background

Cementless reverse shoulder arthroplasty has become increasingly popular because of the improved implant design, porous ingrowth surface, and surgical techniques. When avoiding the risks of cement use, a press-fit arthroplasty stem that has been implanted may not feel immediately stable, especially if the medullary canal size is in between standard stem diameters. To help surgeons improve fixation and avoid overstuffing the medullary canal, we present the matchstick autograft augmentation technique. The use of humeral autograft, analogous to impaction grafting in hip arthroplasty, has been reported to have promising short-term outcomes2,3. This technique of using humeral autograft material, dubbed matchstick autografts because of their shape and size, allows for optimization of humeral stem stability with the option of smaller cementless humeral implants. By avoiding overstuffing of the medullary canal, this technique aims to reduce the incidences of intraoperative fracture, postoperative stress shielding, and potential implant loosening4-6.

Description

Cementless reverse total shoulder arthroplasty is routinely performed via the anterosuperior approach7; however, a deltopectoral approach can be utilized if desired. The canal is sequentially broached with implant trials until the tactile feedback demonstrates axial and rotational stability. In cases in which tactile feedback during implantation demonstrates slight movement, the smaller implant size can be selected and augmented with matchstick autograft. An oscillating saw is utilized to cut the edges of the previously resected humeral head in order to expose the subchondral bone surface. Graft sticks about 20 mm in length and 1 to 3 mm in width are then fashioned. Humeral trials are then implanted with the matchstick grafts placed lengthwise alongside the humeral stem. Axial and rotational press-fit is again assessed. If adequate, the formal humeral implant is selected and implanted in position. As in conventional impaction grafting, the grafts are compressed to the side of the humeral canal, but they offer more corticocancellous structure than bone chips. This technique is applicable even in some fracture scenarios.

Alternatives

When a specific press-fit humeral stem size does not achieve adequate stability, there are typically 3 surgical alternatives. First, a larger stem size can be selected. Second, the implant can be inserted deeper to achieve press-fit stability. Third, cement can be added to fill the medullary canal and create immediate stability.

Rationale

When implanting the humeral prosthesis, the operating surgeon's primary goal is stem stability. When faced with lack of stability, the surgeon can select a larger humeral stem, risking stress shielding; implant the stem deeper, compromising length and risking humeral fracture; or consider a cemented implant. In order to minimize the risk of intraoperative cardiopulmonary events and complicated subsequent revision surgeries8, the use of cement should be avoided if at all possible. Shoulder surgeons have reported grafting techniques, analogous to hip impaction grafting, that have yielded good success3. The technique that we describe utilizes a matchstick structural autograft that helps improve cementless fixation in primary humeral implantation cases and allows for the use of a smaller stem. The structural shape of the graft allows this technique to be utilized even in selected proximal humeral fractures.

Expected Outcomes

Other studies have reported on the use of softer cancellous autografts to stabilize humeral implants in shoulder arthroplasty. In a study of 286 arthroplasties with a minimum follow-up of 2 years, Lucas et al. reported that 267 humeral stems (93.3%) had not subsided3. Humphrey and Bravman used cancellous autograft to achieve metaphyseal centering of the humeral component in 53 patients, with no cases of humeral implant loosening at 12 months2. Lo et al. reported 91% tuberosity healing in their series of cementless reverse total shoulder arthroplasties augmented with matchstick autografts1, with no cases of aseptic humeral stem loosening. Montemaggi et al. used matchstick autografts to augment 46 primary cementless reverse total shoulder arthroplasties and found zero instances of humeral loosening at 1-year follow-up9.

Important Tips

The strongest humeral matchstick grafts come from the subchondral surface.After creating the graft, it is palpated for structural integrity. A stiffer or softer graft can be chosen, depending on surgeon preference.Surgeons can try impacting the graft with humeral trials to assess the stem stability prior to final implantation.

Acronyms and Abbreviations

RTSA = reverse total shoulder arthroplastyFX = fracture3D CT = 3-dimensional computed tomographyXR = x-rayFU = follow-up.

Cementless reverse total shoulder arthroplasty implantation with humeral matchstick autograft augmentation: early radiographic outcomes

BACKGROUND

Humeral-sided complications account for up to 21% of all revision reverse total shoulder arthroplasty (RTSA) surgeries. Stress shielding with large bulky stems can lead to proximal bone resorption per Wolff law, complicating further surgeries. Previously published studies suggest that lowering the metaphyseal implant fill ratio can lead to fewer adaptive radiographic changes and decreased bone resorption. Inspired by these studies, cementless primary RTSA implantation technique with humeral matchstick autografts was proposed to augment cementless humeral constructs, foster the use of a smaller size stem, and create primary stability of the humeral implant even in osteoporotic or in-between size medullary canals. In this study, retrospective review of this cementless RTSA technique with short-term radiographic evaluation was performed.

METHODS

Forty-six nonconsecutive patients underwent primary RTSA with a short-stem cementless prosthesis (Stryker Ascend Flex) augmented by matchstick bone grafting from January to July 2020. Patient demographics were recorded, and follow-up radiographs were retrospectively reviewed to assess metaphyseal fill ratios and incidence of stress shielding at minimum 1-year follow-up. Discrepancies between templated and final stem sizes were recorded, along with all intraoperative and postoperative complications.

RESULTS

Of the 46 patients originally identified, there were 5 men and 41 women with a mean age of 71 years (standard deviation [SD] 7, range 53-88). Mean templated stem size was 4 (SD 2, range 1-8), whereas the mean final implant size was 2 (SD 1, range 1-3). Mean fill ratios were 0.76 (SD 0.06, range 0.54-0.89) along the metaphysis and 0.67 (SD 0.09, range 0.49-0.83) along the diaphysis. There were no intraoperative humeral fractures from implantation. All patients were available for radiographic follow-up with a mean of 19 months (SD 8, range 12-40). There were 3 cases (7%) of proximal humeral stress shielding, with average fill ratios of 0.857 and 0.807 in the metaphysis and diaphysis, respectively. There were 3 patients (7%) who underwent revision surgeries for baseplate failure and periprosthetic humeral fracture. There were no cases of early humeral loosening.

DISCUSSION

Matchstick autograft humeral augmentation is a simple, promising surgical technique with low intraoperative complication rates and good short-term radiographic outcomes. When the implant fill ratio is successfully reduced, there is a possible lower risk of humeral stress shielding. The authors believe this technique can help maximize implant stability in cementless shoulder arthroplasty and preserve humeral bone stock for future revision surgeries.

Implications of humeral short-stem diametral sizing on implant stability

Background

Shoulder arthroplasty humeral stem design has evolved to include various shapes, coatings, lengths, sizes, and fixation methods. While necessary to accommodate patient anatomy characteristics, this creates a surgical paradox of choice. The relationship between the surgeon's selection of short-stem implant size and construct stiffness, resistance to subsidence and micromotion has not been assessed.

Methods

Eight paired cadaveric humeri were reconstructed with surgeon-selected (SS) and 2-mm diametrically larger (SS+2) short-stemmed press-fit implants. Each reconstruction was subjected to 2000 cycles of 90° forward flexion loading, and stem subsidence and micromotion were measured using optical tracking. Compressive stiffness of the stem-bone reconstruction was then assessed by applying a load in-line with the stem axis that resulted in 5 mm of stem subsidence.

Results

Increasing stem size by 2 mm resulted in the construct stiffness more than doubling compared to SS stems (-741 ± 243 N/mm vs. -334 ± 120 N/mm; P = .003; power = 0.971). These larger stems also subsided significantly less than their SS counterparts (SS: 1.2 ± 0.6 mm; SS+2: 0.5 ± 0.5 mm; P = .029; power = 0.66), though there were no significant changes in micromotion (SS: 169 ± 59 μm; SS+2: 187 ± 52 μm; P = .506; power = 0.094).

Conclusions

The results of this study highlight the importance of proper short-stem sizing, as a relatively small 2 mm increase in diametral size was observed to significantly impact construct stiffness, which could increase the risk of stress shielding and implant loosening. Future work should focus on developing tools that objectively quantify bone quality and aid surgeons in selecting the appropriate size short-stem humeral implants for a particular patient.

Stem size prediction in shoulder arthroplasty with preoperative 3D planning

INTRODUCTION

Three-dimensional surgical planning software provides virtual reconstructions of the shoulder with automated joint indices for a preoperative case assessment. The aim of this single center study was to evaluate the concordance between the preoperatively selected humeral components and the final implants used in shoulder arthroplasty.

METHODS

129 cases who had undergone anatomic (n = 16) or reverse shoulder arthroplasty (n = 117) using the same type of uncemented short stem implant and were included for review in this study. The type of arthroplasty, stem size, stem inclination, tray-offset and liner-thickness were noted preoperatively and compared to the final implant specifications used in surgery.

RESULTS

The type of arthroplasty matched the surgical plan in 99.2% of cases, as one case was converted from RSA to TSA. The concordance of planned to implanted stem size was 44.2% and the planned size was in range of one adjacent size in 87.6% of cases. Stem inclination in TSA matched the surgical plan in 50% of cases. Tray offset in RSA was predicted correctly in 65% and liner-thickness matched the surgical plan in 98.3% of cases.

CONCLUSION

Despite a low degree of concordance of planned to implanted stem sizes of 44.2%, the choice of stem size was found to be in range of one adjacent size in 87.6% of cases. Further investigations of other contributing factors are necessary to increase the accuracy of the preoperative selection of humeral implants.

LEVEL OF EVIDENCE

level IV, retrospective case study.

Humeral stem with low filling ratio reduces stress shielding in primary reverse shoulder arthroplasty

PURPOSE

Some patients show severe humeral bone stress shielding even one year after press-fit humeral stem, which can be a risk factor for implant durability. This study compared humeral stress shielding and clinical outcomes between high and low filling ratio (HFR and LFR) stems in primary reverse shoulder arthroplasty (RSA).

METHODS

From 2015 to 2020, 104 patients who underwent RSA with a non-cemented standard-length humeral stem were examined. The humeral stems included large press-fit stems (HFR group, 53 patients) or small non-press-fit stems with autogenous cancellous bone grafting (LFR group, 51 patients). The radiologic and clinical outcomes were compared between the groups one year post-operatively.

RESULTS

One patient in the LFR group with early infectious dislocation was excluded from the 1-one year evaluation. No stress shielding was observed in 27/50 (54.0%) and 5/53 (9.4%) of patients in the LFR and HFR groups, while 3/50 (6%) and 19/53 (35.8%) patients showed high-stress shielding, respectively. However, the stem alignment change, subsidence, complications and evidence of loosening did not differ between the groups. The final range-of-motion and functional scores were significantly poorer in the LFR group than those in the HFR group, although the difference was minimal.

CONCLUSION

Even at one year follow-up, patients receiving LFR stems with autogenous bone grafting had significantly less humeral stress shielding compared to patients with HFR stem with press-fit in primary RSA, without compromising stem stability.

Shoulder Hemiarthroplasty with Nonprosthetic Glenoid Arthroplasty: The Ream-and-Run Procedure

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Glenoid component wear and loosening are the principal failure modes of anatomic total shoulder arthroplasty (aTSA).

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The ream-and-run (RnR) procedure is an alternative glenohumeral arthroplasty for patients who wish to avoid the risks and limitations of a prosthetic glenoid component.

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During the RnR procedure, the arthritic glenoid is conservatively reamed to a single concavity, while the prosthetic humeral component and soft tissues are balanced to provide both mobility and stability of the joint.

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The success of the RnR procedure depends on careful patient selection, preoperative education and engagement, optimal surgical technique, targeted rehabilitation, and close postoperative communication between the surgeon and the patient.

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While the RnR procedure allows high levels of shoulder function in most patients, the recovery can be longer and more arduous than with aTSA.

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Patients who have undergone an RnR procedure occasionally require a second closed or open procedure to address refractory shoulder stiffness, infection, or persistent glenoid-sided pain. These second procedures are more common after the RnR than with aTSA.

Anatomic Total Shoulder Arthroplasty with All-Polyethylene Glenoid Component for Primary Osteoarthritis with Glenoid Deficiencies

This study evaluated the ability of shoulder arthroplasty using a standard glenoid component to improve patient self-assessed comfort and function and to correct preoperative humeral-head decentering on the face of the glenoid in patients with primary glenohumeral arthritis and type-B2 or B3 glenoids.

Cementless curved short stem shoulder prostheses with a proximal porous coating: ingrowth properties at 2-5 years of radiological follow-up with clinical correlation

BACKGROUND

Little is known about the way the newest generation of stems integrate into the proximal humerus and their effect on the surrounding bone. Factors that may influence ingrowth have not been investigated.

METHODS

A consecutive cohort study was conducted that examined 74 anatomical, reverse, or pyrocarbon hemiprostheses, using a curved modular short stem with a proximal porous coating 2-5 years postoperatively (mean 35 months). X-rays were reviewed by 2 examiners independently. Bone loss was scored with 1 point per zone with partial and 2 points per zone with complete resorption (10 zones). The Constant score was used for clinical correlation. Multiple linear regression was employed to investigate correlations between variables.

RESULTS

No subsidence or shift of the stems occurred. Two of 74 patients showed 1 zone of periprosthetic lucency of 1 mm. The filling ratio averaged 0.54 (range: 0.36-0.75). Thirty patients (40.5%) displayed bone resorption, first seen at 16.6 months (range: 3-40 months), commonly in zones 1 and 5. A total of 22 patients had ≥1 zone with partial resorption, and 8 (10.8%) developed full thickness resorption after 32 (range: 10-49) months.One new finding was that female sex and older age accounted for 51% of the variation of the filling ratio. A high filling ratio, especially when >0.55, correlated with bone resorption (P < .001). Age, sex, and prosthesis type did not directly predict bone resorption. Bony sclerosis correlated with a high filling ratio (P = .019) and thereby indirectly with resorption. A direct correlation between sclerosis and resorption was narrowly insignificant (P = .058) once correcting for the filling ratio. Reverse shoulder prosthesis had a higher filling ratio than total shoulder prosthesis patients (P < .001), resulting indirectly in more bone resorption. The preoperative diagnosis did not significantly correlate with the filling ratio (P = .59) or the resorption score (P = .69). A varus or valgus alignment did not predict resorption (P = .21) or the formation of sclerotic lines (P = .93). Bone loss did not correlate with clinical results.

CONCLUSIONS

These short stems are firmly anchored 2-5 years postoperatively. However, significant bone loss, linked to a high filling ratio (>0.55), is observed proximally around these stems. The development of sclerotic lines around the stem indicates oversizing. Other factors were not found to have a significant effect on stem ingrowth. The implantation of stems with a large filling ratio is more common in older females and in patients receiving reverse shoulder prosthesis. Autologous impaction bone grafting could downsize the required stem. If adequate hold is not afforded by a suitably small stem, cementation is advisable.

Automated detection and classification of shoulder arthroplasty models using deep learning

OBJECTIVE

To develop and evaluate the performance of deep convolutional neural networks (DCNN) to detect and identify specific total shoulder arthroplasty (TSA) models.

MATERIALS AND METHODS

We included 482 radiography studies obtained from publicly available image repositories with native shoulders, reverse TSA (RTSA) implants, and five different TSA models. We trained separate ResNet DCNN-based binary classifiers to (1) detect the presence of shoulder arthroplasty implants, (2) differentiate between TSA and RTSA, and (3) differentiate between the five TSA models, using five individual classifiers for each model, respectively. Datasets were divided into training, validation, and test datasets. Training and validation datasets were 20-fold augmented. Test performances were assessed with area under the receiver-operating characteristic curves (AUC-ROC) analyses. Class activation mapping was used to identify distinguishing imaging features used for DCNN classification decisions.

RESULTS

The DCNN for the detection of the presence of shoulder arthroplasty implants achieved an AUC-ROC of 1.0, whereas the AUC-ROC for differentiation between TSA and RTSA was 0.97. Class activation map analysis demonstrated the emphasis on the characteristic arthroplasty components in decision-making. DCNNs trained to distinguish between the five TSA models achieved AUC-ROCs ranging from 0.86 for Stryker Solar to 1.0 for Zimmer Bigliani-Flatow with class activation map analysis demonstrating an emphasis on unique implant design features.

CONCLUSION

DCNNs can accurately identify the presence of and distinguish between TSA & RTSA, and classify five specific TSA models with high accuracy. The proof of concept of these DCNNs may set the foundation for an automated arthroplasty atlas for rapid and comprehensive model identification.

Current state of short-stem implants in total shoulder arthroplasty: a systematic review of the literature

Background

Humeral stem length in anatomic total shoulder arthroplasty (TSA) continues to decrease in an attempt to preserve bone. Outcomes following short-stem TSA are not well documented. The purpose was to systematically review and report the outcomes and revisions following short-stem humeral implants for TSA.

Methods

A systematic review was registered with PROSPERO and performed with PRISMA guidelines using 3 publicly available free databases. Therapeutic clinical outcome investigations reporting TSA outcomes of short-stem implants with levels of evidence I-IV were eligible for inclusion. All study, subject, and surgical technique demographics were analyzed and described.

Results

Thirteen studies were included (average follow-up: 33 months, range 24-84 months; 8 studies [62%] were multicenter and 6 [46%] were from Europe). All studies were published in the last 8 years, and almost all (12/13, 92%) reported results of uncemented components. Most of the studies (9/13, 70%) reported results from the Aequalis Ascend or Ascend Flex Stem (Tornier). Improvements were seen in all measured range of motion planes and patient-reported outcome scores. Complications were infrequent, with a 2% humeral loosening rate, a 3% overall revision rate, and a 1% rate of revision for aseptic humeral loosening. Radiographic results showed a 13% rate of radiolucent lines, a 16% rate of condensation lines, and a 22% rate of calcar osteolysis.

Conclusion

Short-stem TSA humeral implants provide excellent results, with low revision rates in the short term. Long-term follow-up will be necessary to understand the clinical impact of radiographic calcar osteolysis.

Radiographic outcomes of impaction-grafted standard-length humeral components in total shoulder and ream-and-run arthroplasty: is stress shielding an issue?

BACKGROUND

The purpose of this study was to evaluate humeral stress shielding in shoulder arthroplasties performed with a smooth, standard-length humeral stem fixed with impaction autografting.

METHODS

Two-year outcomes were evaluated for 48 ream-and-run arthroplasties and 78 total shoulder arthroplasties (TSAs) performed at a single institution. Postoperative radiographs were analyzed for adaptive changes, calcar osteolysis, and component shift or subsidence. Radiographic outcomes were analyzed for associations with patient demographic characteristics, humeral stem filling ratios, and glenoid loosening; clinical outcomes were assessed using the Simple Shoulder Test.

RESULTS

At 2 years after surgery, the ream-and-run procedures showed partial calcar osteolysis in 9 cases (19%). The TSAs showed partial calcar osteolysis in 19 cases (24%) and complete calcar osteolysis in 2 (3%). Humeral component subsidence or component shift was observed in 3 ream-and-run procedures (6%) and in 8 TSAs (10%). These radiographic findings were not significantly associated with patient demographic characteristics, canal-filling ratios, or clinical outcomes.

CONCLUSION

When inserted with impaction autografting, a smooth, standard-length humeral stem offers a secure bone-preserving approach for humeral component fixation in shoulder arthroplasty. These results with a conventional prosthesis can serve as a basis for comparison for new component designs and fixation methods.

Clinical effectiveness and safety of the extended humeral head arthroplasty for selected patients with rotator cuff tear arthropathy

BACKGROUND

Cuff tear arthropathy is commonly managed with a reverse total shoulder arthroplasty (RTSA). A humeral hemiarthroplasty with an extended humeral head may provide a less invasive alternative for selected patients with cuff tear arthropathy if the shoulder has preserved active elevation. Because evidence regarding this procedure is limited, we investigated its safety and efficacy in treating selected patients with cuff tear arthropathy.

METHODS

We analyzed the preoperative characteristics, surgical findings, and clinical outcomes for patients selected for extended head hemiarthroplasty.

RESULTS

For 42 patients with 2-year follow-up, there were no complications or revisions. The Simple Shoulder Test score improved from a median of 3.0 to 8.0 (P < .001). The median percentage of maximal possible improvement was 50% (P < .001). The percentage of patients able to perform each of the functions of the Simple Shoulder Test was significantly improved; for example, the ability to sleep comfortably increased from 19% to 71%, and the ability to place a coin on the shelf at shoulder level increased from 38% to 86% (P < .001).

CONCLUSIONS

There are circumstances in which RTSA is clearly the preferred procedure for cuff tear arthropathy, including pseudoparalysis, anterosuperior escape, and glenohumeral instability; however, in shoulders with preserved active motion and stability of the humeral head provided by an intact coracoacromial arch, the extended head humeral arthroplasty can enable selected patients to realize improved comfort and function without the potential risks of RTSA. Extended humeral head hemiarthroplasty can provide a safe and effective alternative for the management of selected patients with rotator cuff tear arthropathy and preserved active motion.

The emerging role of circRNAs and their clinical significance in human cancers

Circular RNA (circRNA), a recently discovered subclass of non-coding RNAs (ncRNAs), forms a covalently closed loop with neither a 5' cap structure nor a 3' polyadenylated tail. Generated from precursor mRNA (pre-mRNA) through "backsplicing" (a type of alternative RNA splicing), the majority of circRNAs are located in the cytoplasm and are widespread among living organisms. They are stable and conserved and exhibit spatiotemporal-specific expression. CircRNAs are known to be involved in the development and progression of multiple diseases, including cancer, by acting as microRNA (miRNA) sponges and by regulating processes such as transcription and translation. The extensively aberrant expression profiles of circRNAs in multiple cancerous tissues make these molecules promising diagnostic biomarkers and therapeutic targets for cancer. Here, we briefly review the characteristics, biogenesis, classification, and functions of circRNAs, with a particular focus on the role of circRNAs in various cancers.

A Method to Facilitate Improved Positioning of a Reverse Prosthesis Stem During Arthroplasty Surgery: The Metaphyseal-centering Technique

Supplemental Digital Content is available in the text.

Because humeral head offset values vary widely from patient to patient, the final position of the proximal portion of a stemmed humeral prosthesis will sometimes not align well with respect to the center of rotation of the humeral head. This is especially notable when a humeral component with limited modularity is used. To address this problem, a prosthesis-specific method is presented for orienting a reverse shoulder humeral component (AltiVate Reverse, DJO Surgical, Austin, TX). With the metaphyseal-centering technique, priority is given to the positioning of the shell portion of the prosthesis over that of the stemmed portion during bone preparation. To ensure that a centralized shell position is achieved within the proximal humerus bone in patients with extreme posterior and medial offset measurement values, the stem portion of the humeral prosthesis is sometimes purposely undersized and positioned eccentrically within the humeral diaphysis. Bone autograft is used in such cases to improve the fit and fixation of the stem within the humeral canal. The metaphyseal-centering technique facilitates: (1) consistent positioning of the shell portion of the humeral prosthesis relative to the center of rotation of the humeral head, and (2) conversion from a standard to a reverse prosthesis, or vice versa, during revision surgery without the need for stem removal or alteration of the humerus bone. Preliminary outcomes of this surgical technique are encouraging, but formal studies are warranted to validate its clinical utility and longevity of results.

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.

Functional Outcomes of the Ream-and-Run Shoulder Arthroplasty: A Concise Follow-up of a Previous Report

We previously reported the results at an average of 4.5 years after treatment of 176 patients with the ream-and-run arthroplasty. In the present study, we present the patient self-reported functional outcomes and clinical implant survival of the original cohort at a mean of 10 years (range, 5 to 16 years). Twenty-eight (16%) of the 176 patients had a subsequent procedure, 11 (6%) died, and 30 (17%) had <5 years of follow-up. The Simple Shoulder Test (SST) score at the time of the latest follow-up was a median of 11 points (interquartile range, 9 to 12 points) and a mean (and standard deviation) of 10 ± 2.6 points, out of a possible 12 points. The present study demonstrates that the improvement in function and comfort derived from the ream-and-run procedure can be sustained at the time of mid-term follow-up.

LEVEL OF EVIDENCE

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

Does Postoperative Glenoid Retroversion Affect the 2-Year Clinical and Radiographic Outcomes for Total Shoulder Arthroplasty?

BACKGROUND

While glenoid retroversion and posterior humeral head decentering are common preoperative features of severely arthritic glenohumeral joints, the relationship of postoperative glenoid component retroversion to the clinical results of total shoulder arthroplasty (TSA) is unclear. Studies have indicated concern for inferior outcomes when glenoid components are inserted in 15° or more retroversion.

QUESTIONS/PURPOSES

In a population of patients undergoing TSA in whom no specific efforts were made to change the version of the glenoid, we asked whether at 2 years after surgery patients having glenoid components implanted in 15° or greater retroversion had (1) less improvement in the Simple Shoulder Test (SST) score and lower SST scores; (2) higher percentages of central peg lucency, higher Lazarus radiolucency grades, higher mean percentages of posterior decentering, and more frequent central peg perforation; or (3) a greater percentage having revision for glenoid component failure compared with patients with glenoid components implanted in less than 15° retroversion.

METHODS

Between August 24, 2010 and October 22, 2013, information for 201 TSAs performed using a standard all-polyethylene pegged glenoid component were entered in a longitudinally maintained database. Of these, 171 (85%) patients had SST scores preoperatively and between 18 and 36 months after surgery. Ninety-three of these patients had preoperative radiographs in the database and immediate postoperative radiographs and postoperative radiographs taken in a range of 18 to 30 months after surgery. Twenty-two patients had radiographs that were inadequate for measurement at the preoperative, immediate postoperative, or latest followup time so that they could not be included. These excluded patients did not have substantially different mean age, sex distribution, time of followup, distribution of diagnoses, American Society of Anesthesiologists class, alcohol use, smoking history, BMI, or history of prior surgery from those included in the analysis. Preoperative retroversion measurements were available for 11 (11 shoulders) of the 22 excluded patients. For these 11 shoulders, the mean (± SD) retroversion was 15.8° ± 14.6°, five had less than 15°, and six had more than 15° retroversion. We analyzed the remaining 71 TSAs, comparing the 21 in which the glenoid component was implanted in 15° or greater retroversion (mean ± SD, 20.7° ± 5.3°) with the 50 in which it was implanted in less than 15° retroversion (mean ± SD, 5.7° ± 6.9°). At the 2-year followup (mean ± SD, 2.5 ± 0.6 years; range, 18-36 months), we determined the latest SST scores and preoperative to postoperative improvement in SST scores, the percentage of maximal possible improvement, glenoid component radiolucencies, posterior humeral head decentering, and percentages of shoulders having revision surgery. Radiographic measurements were performed by three orthopaedic surgeons who were not involved in the care of these patients. The primary study endpoint was the preoperative to postoperative improvement in the SST score.

RESULTS

With the numbers available, the mean (± SD) improvement in the SST (6.7 ± 3.6; from 2.6 ± 2.6 to 9.3 ± 2.9) for the retroverted group was not inferior to that for the nonretroverted group (5.8 ± 3.6; from 3.7 ± 2.5 to 9.4 ± 3.0). The mean difference in improvement between the two groups was 0.9 (95% CI, - 2.5 to 0.7; p = 0.412). The percent of maximal possible improvement (%MPI) for the retroverted glenoids (70% ± 31%) was not inferior to that for the nonretroverted glenoids (67% ± 44%). The mean difference between the two groups was 3% (95% CI, - 18% to 12%; p = 0.857). The 2-year SST scores for the retroverted (9.3 ± 2.9) and the nonretroverted glenoid groups (9.4 ± 3.0) were similar (mean difference, 0.2; 95% CI, - 1.1 to 1.4; p = 0.697). No patient in either group reported symptoms of subluxation or dislocation. With the numbers available, the radiographic results for the retroverted glenoid group were similar to those for the nonretroverted group with respect to central peg lucency (four of 21 [19%] versus six of 50 [12%]; p = 0.436; odds ratio, 1.7; 95% CI, 0.4-6.9), average Lazarus radiolucency scores (0.5 versus 0.7, Mann-Whitney U p value = 0.873; Wilcoxon rank sum test W = 512, p value = 0.836), and the mean percentage of posterior humeral head decentering (3.4% ± 5.5% versus 1.6% ± 6.0%; p = 0.223). With the numbers available, the percentage of patients with retroverted glenoids undergoing revision (0 of 21 [0%]) was not inferior to the percentage of those with nonretroverted glenoids (three of 50; [6%]; p = 0.251).

CONCLUSION

In this small series of TSAs, postoperative glenoid retroversion was not associated with inferior clinical results at 2 years after surgery. This suggests that it may be possible to effectively manage arthritic glenohumeral joints without specific attempts to modify glenoid version. Larger, longer-term studies will be necessary to further explore the results of this approach.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Clinical and Radiographic Outcomes of the Ream-and-Run Procedure for Primary Glenohumeral Arthritis

BACKGROUND

The ream-and-run procedure can provide improvement in shoulder function and comfort for selected patients with primary glenohumeral arthritis who wish to avoid a prosthetic glenoid component. The purpose of this study was to evaluate factors associated with medialization of the humeral head after this procedure as well as the relationship of medialization to the clinical outcome.

METHODS

We collected patient, shoulder, and procedure characteristics along with Simple Shoulder Test (SST) scores before surgery and at the time of follow-up. Medialization was determined by comparing the position of the humeral head prosthesis in relation to the scapula on postoperative baseline radiographs made within 6 weeks after surgery with that on comparable follow-up radiographs made ≥18 months after surgery.

RESULTS

Two-year clinical outcomes were available for 101 patients (95% were male). Comparable radiographs at postoperative baseline and follow-up evaluations were available for 50 shoulders. For all patients, the mean SST score (and standard deviation) increased from 4.9 ± 2.8 preoperatively to 10.3 ± 2.4 at the latest follow-up (p < 0.001). Significant clinical improvement was observed for glenoid types A2 and B2. Shoulders with a type-A2 glenoid morphology, with larger preoperative scapular body-glenoid angles, and with lower preoperative SST scores, were associated with the greatest clinical improvement. Clinical outcome was not significantly associated with the amount of medialization.

CONCLUSIONS

The ream-and-run procedure can be an effective treatment for advanced primary glenohumeral osteoarthritis in active patients. Further study will be necessary to determine whether medialization affects the clinical outcome with follow-up of >2 years.

LEVEL OF EVIDENCE

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