The vertical humeral osteotomy for stem removal in revision shoulder arthroplasty: results and technique

Cement-within-cement technique in revision reverse shoulder arthroplasty: A systematic review of biomechanical data, and clinical outcomes

Background

The purpose of this research was to systematically review and summarize the existent literature on the use of the cement-within-cement technique for revision reverse shoulder arthroplasty (RSA).

Methods

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed/Medline, Scopus, and EMBASE databases were searched for relevant studies. We included clinical studies in which patients underwent RSA revision using the cement-within-cement method for the humeral component, and studies that evaluated the biomechanical performance or described the surgical technique. The methodological risk of bias was assessed using the methodological index for non-randomized studies scale.

Results

The search yielded 516 records, of which two clinical and one biomechanical study met the inclusion criteria, involving 133 patients and 20 synthetic humeri. The intraoperative complication rate was 18%, all of which involved humeral fractures. The postoperative complication rate was 18% among 35 patients. The combined re-revision rate was 9%, with a reported humeral component survival rate of 100% at 2 years and 96% at 5 years. Periprosthetic fractures (1.5%) and humeral stem loosening (1.5%) led to re-revision surgeries in all cases. All studies reported improved patient-reported outcomes and range of motion. The biomechanical study demonstrated increased rotational stability in models that used larger humeral stems.

Conclusions

The cement-within-cement method is a viable option for revision RSA, showing positive outcomes in terms of stability, range of motion, and clinical functional scores. The complication rate is similar to that of other revision strategies; however, the prevalence of intraoperative humeral fractures may be higher. Nevertheless, future studies with larger sample sizes and longer follow-up periods are needed to refine patient selection, determine the efficacy of long-term use, and identify factors that may influence outcomes after the cement-within-cement revision technique. Further research on an optimized stem fixation strategy is needed to improve outcomes and reduce avoidable complications.

Level of evidence

Level IV, Systematic reviews.

Spatial Anatomy of the Radial Nerve in the Extended Deltopectoral Approach

The goal of this study was to define safe zones to prevent radial nerve injury in an extended deltopectoral approach. Relative distances of the upper margin (UMRN) and lower margin (LMRN) of the radial nerve to the proximal and distal borders of the pectoralis major and deltoid insertions were measured in 20 cadaveric arms. Four proximal humeral zones were identified (zone I, proximal border of the pectoralis major tendon to the proximal border of the deltoid tendon; zone II, proximal border of the deltoid tendon to the distal border of the pectoralis major tendon; zone III, distal border of the pectoralis major tendon to the distal border of the deltoid tendon; and zone IV, distal to the distal border of the deltoid tendon). On fluoroscopic measurement, mean distances between the UMRN and the proximal border of the pectoralis major tendon and the proximal border of the deltoid tendon were 71.6±2.1 mm and 26.2±2.5 mm, respectively. The incidence of the radial nerve in the spiral groove within each defined zone was as follows: zone I, 0%; zone II, 50%; zones III and IV, 100%. There was a significant association between anatomic zone and radial nerve entry into the spiral groove, χ²(3, N=88)=64.53, P<.001. The proximal border of the pectoralis major tendon to the proximal border of the deltoid tendon (zone I) is a safe location to avoid injury to the radial nerve. We recommend placing cerclage wires proximal to zone I from lateral to medial to avoid entrapment of the radial nerve. [Orthopedics. 2023;46(1):e31-e37.].

Pectoralis-major-pedicled bone window for revision of a shoulder arthroplasty

PURPOSE

The aim of this study is to review our experience with the pectoralis-major-pedicled bone window for the revision of shoulder arthroplasty.

METHODS

This study used the retrospective case series of six patients who underwent a pectoralis-major-pedicled bone window for revision of shoulder arthroplasty, with a minimum follow-up of 2 years. Demographic, clinical, and radiological data were analyzed.

RESULTS

The mean age of the included patients was 72.6 years old (standard deviation (SD) 4.7), and 83.3% were women (5/1). The mean follow-up was 36.6 months (range 25-48 months). Five patients had a shoulder hemiarthroplasty and one patient a reverse shoulder arthroplasty. The indications for revision were pain in five patients and recurrent dislocation in one patient. No intraoperative complications were found. One patient developed a wound infection that required debridement and a two-stage revision. Despite complications, 2 years after surgery, the range of motions and functional scores were improved from preoperative levels. The difference between preoperative and postoperative VAS pain scores was 7.1 points (p < 0.001). The difference between preoperative and postoperative CSS and ASES questionnaires were 32 and 31.6 points, respectively (p < 0.001). At the final follow-up, all radiographs showed bone union of the osteotomy, good fixation of all components, without evidence of prosthetic loosening or migration.

CONCLUSIONS

Revision of a shoulder arthroplasty using a pectoralis-major-pedicled bone window can be an effective treatment that can yield pain relief; however, improvements in motion and function were difficult to achieve.

Symptomatic aseptic loosening of a short humeral stem following anatomic total shoulder arthroplasty

INTRODUCTION

The rate of aseptic humeral component loosening with standard-length stems is historically so low (0.3%) that presence of humeral loosening was given substantial weight in defining periprosthetic shoulder infection by the International Consensus Meeting (ICM) in 2018. This study aims to confirm that the historically low rate of humeral stem aseptic loosening is not affected by the adoption of a novel short humeral stem.

METHODS

Following institutional review board approval, this retrospective multi-institutional study was undertaken. A review of anatomic total shoulder arthroplasty (TSA) cases at 3 institutions provided 184 shoulders that received TSA with a grit-blasted, rectangular short humeral stem without ingrowth coating (Univers Apex; Arthrex). The average patient age was 62.1 years (range: 30-84), and 57.1% (105/184) were male. One-year radiographic follow-up was achieved in 64.7%. Patient clinical charts were reviewed for onset of newly painful shoulders, radiographic evidence of loosening, and return to the operating room for any reason. All patients with concern for clinically significant humeral loosening underwent workup for periprosthetic shoulder infection. Immediate postoperative films were reviewed to identify any differences in prosthetic canal fit. The definition of periprosthetic shoulder infection used was provided by the recent ICM shoulder guidelines.

RESULTS

Twenty-three (12.5%) patients presented with a painful shoulder and radiographic concern for potential humeral loosening at a mean follow-up of 1.5 years (range: 1.5 months-3.4 years). Thirteen (7.1%) of these underwent revision shoulder arthroplasty where a loose stem was confirmed. All revisions underwent tissue culture, and 3 cases were consistent with probable or possible periprosthetic infection at the time of revision arthroplasty. The rate of symptomatic aseptic humeral loosening in this series was 10.9% (20/184), with 5.4% undergoing revision surgery. Patients with symptomatic aseptic humeral loosening were more likely to be male (90.5%) than those patients without symptoms (52.8%, P < .001). There were no differences in canal fit between patients with concern for symptomatic loosening and those with pain-free, stable implants.

CONCLUSION

In this multisurgeon, multicenter study, the early humeral loosening rate for this stem design far outpaces previously reported rates, and this study likely under-reports the true incidence of clinically significant loosening as it only contains limited short-term follow-up. The perception that humeral loosening is nearly pathognomonic for periprosthetic shoulder infection should be reconsidered for certain short humeral stem designs.

Outcome and complications following revision shoulder arthroplasty : a systematic review and meta-analysis

AIMS

It is important to understand the rate of complications associated with the increasing burden of revision shoulder arthroplasty. Currently, this has not been well quantified. This review aims to address that deficiency with a focus on complication and reoperation rates, shoulder outcome scores, and comparison of anatomical and reverse prostheses when used in revision surgery.

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) systematic review was performed to identify clinical data for patients undergoing revision shoulder arthroplasty. Data were extracted from the literature and pooled for analysis. Complication and reoperation rates were analyzed using a meta-analysis of proportion, and continuous variables underwent comparative subgroup analysis.

RESULTS

A total of 112 studies (5,379 shoulders) were eligible for inclusion, although complete clinical data was not ubiquitous. Indications for revision included component loosening 20% (601/3,041), instability 19% (577/3,041), rotator cuff failure 17% (528/3,041), and infection 16% (490/3,041). Intraoperative complication and postoperative complication and reoperation rates were 8% (230/2,915), 22% (825/3,843), and 13% (584/3,843) respectively. Intraoperative and postoperative complications included iatrogenic humeral fractures (91/230, 40%) and instability (215/825, 26%). Revision to reverse total shoulder arthroplasty (TSA), rather than revision to anatomical TSA from any index prosthesis, resulted in lower complication rates and superior Constant scores, although there was no difference in American Shoulder and Elbow Surgeons scores.

CONCLUSION

Satisfactory improvement in patient-reported outcome measures are reported following revision shoulder arthroplasty; however, revision surgery is associated with high complication rates and better outcomes may be evident following revision to reverse TSA. Cite this article: Bone Jt Open 2021;2(8):618-630.

A Tensionable Suture-based Cerclage Is an Alternative to Stainless Steel Cerclage Fixation for Stabilization of a Humeral Osteotomy During Shoulder Arthroplasty

INTRODUCTION

Fixation of periprosthetic humeral fractures is most commonly obtained with steel-based wires or cables; however, disadvantages with these constructs are numerous. Suture-based cerclages offer the advantage of easy handling, less radiographic interference, and risk of metallosis, as well as decreased risk of cutting into the soft humeral bone. Therefore, the purpose of this study was to compare a suture-based cerclage to a stainless steel wire cerclage (SSWC) for stabilization of the humerus during shoulder arthroplasty.

METHODS

In part I of the study, SSWC fixation was compared with single-looped tape cerclage and a double-looped tape cerclage (DLTC) fixation. In part II, a subsidence test was performed on 12 cadaveric humeri. After an osteotomy, the humeri were secured with either a SSWC or DLTC. Subsequently, a metal wedge was introduced into the humerus to simulate the stem of a shoulder arthroplasty.

RESULTS

In part I, load to 2-mm displacement was significantly higher for the DLTC construct compared with the SSWC construct (2,401 ± 483 N versus 750 ± 33 N; P < 0.0001). Load to failure was 935 ± 143 N with the SSWC, 1,737 ± 113 N with the single-looped tape cerclage, and 4,360 ± 463 N with the DLTC constructs, and all differences were statistically significant (P < 0.05). In part II, load at 20-mm subsidence was higher for the DLTC (320 ± 274 N) compared with the SSWC (247 ± 137 N), but no significant difference was observed (P > 0.05). However, gap displacement at 20 mm subsidence was significantly lower with the DLTC construct (0.33 ± 0.31 mm versus 0.77 ± 0.23 mm; P = 0.009). Load to failure was higher with the DLTC construct compared with the SSWC construct (4,447 ± 2,325 N versus 1,880 ± 1,089 N; P = 0.032), but the final gap displacement did not differ significantly (DLTC 5.23 ± 6.63 mm versus SSWC 6.03 ± 8.82 mm; P > 0.05).

DISCUSSION

A DLTC has higher load to failure and trends toward lower gap displacement compared with a SSWC. The DLTC construct may therefore be a viable alternative for fixation of periprosthetic fractures or osteotomies of the humeral shaft during shoulder arthroplasty.

Primary reverse shoulder replacement with a short stem: A systematic literature review

Background

Total shoulder arthroplasty implant designs have continued to evolve over the years. One recent change has been the shortening of the humeral component to preserve bone stock and to facilitate revision surgery. Despite promising clinical results, radiographic bone adaptions occur frequently in short-stem total shoulder arthroplasty, and limited data exist on short-stem reverse shoulder arthroplasty (RSA). The purpose of this systematic review was to provide an overview about the functional and radiographic outcomes after an uncemented short-stem RSA, as well as identify areas of clinical importance that are underreported in the current literature.

Methods

A systematic review of the literature was performed in accordance with the PRISMA guidelines using PubMed, Cochrane Central Register of Controlled Trials, and EMBASE. Clinical outcome studies reporting on short-stem RSA outcomes with evidence level I-IV were included. Demographics, clinical and radiological outcomes, as well as complications and revision data were systematically analyzed and described.

Results

Ten studies, published between 2014 and 2019, reporting on 555 shoulders with a mean follow-up of 32 months (range, 20-99.6 months) met the inclusion criteria. For all studies cuff tear arthropathy was the main indication for RSA (36%), followed by primary osteoarthritis (20%). Clinical outcome was reported in nine of ten studies, with range of motion improving in all studies. Six of the seven studies that used the Constant score (CS) demonstrated significant improvement (27.9 points to 69.3 points in weighted means). All studies reported on radiographic changes and bone adaptions. Among these, scapular notching was the most commonly observed (60 out of 327 cases, 18%) but without any described implication on clinical outcomes. No stem loosening was recorded at any final follow-up. A total of 63 complications (12.9%) were reported, with scapula fractures being the most commonly reported complication. Revision surgery was necessary in 24 cases (4.9%).

Conclusion

Good clinical results, comparable with long-stem RSAs, are reported at short-term follow-up for short-stem RSAs. Humeral bone adaptions occur frequently but aseptic stem loosening is not a matter of concern at short-term follow-up. An area of clinical importance that is under-reported is the relation between filling ratio and stem alignment in short-stem RSA.

Early migration of stemless and stemmed humeral components after total shoulder arthroplasty for osteoarthritis-study protocol for a randomized controlled trial

BACKGROUND

Glenohumeral osteoarthritis can, in the most severe cases, require surgery with insertion of a shoulder arthroplasty. A design with a stem in the humeral bone canal is currently regarded as the standard treatment option in patients who have an intact rotator cuff function, but complications related to the stem including humeral fractures can have devastating consequences. By using a stemless humeral component, stem-related complications can be reduced. The aim of this study is to compare the Comprehensive Nano stemless total shoulder arthroplasty (intervention group) with the Comprehensive stemmed total shoulder arthroplasty (control group).

MATERIALS AND METHODS

This is a randomized controlled trial comparing the stemless and the stemmed total shoulder arthroplasty. All Danish citizens with glenohumeral osteoarthritis indicating a total shoulder arthroplasty referred to the orthopedic department at Copenhagen University Hospital in Herlev/Gentofte will be offered participation. The following exclude from participation: below 18 years of age, cognitive or linguistic impairment, insufficient function of the rotator cuff, poor bone quality, and ASA groups 4-5. A total of 122 patients will be included of which 56 will be part of a radiostereometric analysis (RSA) study of humeral component migration. The primary outcomes are magnitude of migration of the humeral component assessed by RSA and patient-reported outcome by Western Ontario Osteoarthritis of the Shoulder index (WOOS). The secondary outcomes are additional patient-reported outcomes, functional outcome, readmission, complications, revisions, and changes in bone mineral density (BMD) of the proximal humerus assessed by duel energy x-ray absorptiometry (DXA) and economy (cost-utility analysis). The patients are examined before the operation and 3, 6, 12, and 24 months postoperative.

DISCUSSION

To our knowledge, RSA has never been used to access migration of a stemmed or a stemless humeral component nor has the stemmed and the stemless humeral component been compared with regard to pain relief and shoulder function in a randomized clinical trial. Today, the two designs are considered equal in the treatment of osteoarthritis. The study will provide surgeons and patients with information about shoulder arthroplasty for osteoarthritis and assist them in decision-making.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04105478 . Registered on 25 September 2019.

Periprosthetic Fractures in Reverse Total Shoulder Arthroplasty: Current Concepts and Advances in Management

PURPOSE OF REVIEW

Expanded indications for reverse total shoulder arthroplasty (RSA) have raised awareness of associated complications, including periprosthetic fractures. The purpose of this article was to provide a comprehensive update on how, when, and why RSA-related periprosthetic fractures occur, as well as to describe the current treatment strategies.

RECENT FINDINGS

Periprosthetic acromial and scapular spine fractures occur in up to 4.3% of cases and periprosthetic humeral fractures occur in approximately 3.5% of RSA procedures. Fractures of the coracoid process and clavicle have also been reported. Current literature has identified several risk factors for intraoperative or postoperative fracture, including underlying osteoporosis, revision arthroplasty, use of a superiorly placed screw during metaglene fixation, and disruption of the scapular ring by transection of the coracoacromial ligament. Periprosthetic fracture associated with RSA is a clinically significant event that warrants prolonged postoperative vigilance, timely diagnosis, and shared patient decision-making regarding treatment. Further research is needed to identify optimal treatment strategies and characterize long-term clinical outcomes following RSA-related periprosthetic fracture.

Clavicular osteotomy in complicated revision of total shoulder arthroplasty: indications, surgical technique, and outcomes

PURPOSE

Adequate exposure in revision of total shoulder arthroplasty (TSA) is important for optimal prosthesis placement and functional results. A clavicular osteotomy in difficult cases of revision TSA is a useful surgical technique that increases the superior exposure area, provides safer dissection, minimizes damage to the anterior deltoid muscle, improves glenoid access, and allows for superior dislocation of the humeral component. There is a paucity of literature analyzing the clavicular osteotomy during challenging cases of revision TSA. The aims of this study were to describe the application, surgical technique, and outcomes of revision TSA with a clavicular osteotomy.

METHODS

This was a retrospective study of consecutive patients who underwent revision TSA with a clavicle osteotomy at a single institution (2004-2016). A curved longitudinal clavicular osteotomy is created parallel to the origin of the anterior deltoid muscle. This allows for lateral reflection of the osteotomy and anterior deltoid muscle to significantly increase superior exposure and reduce damage to remaining deltoid muscle fibres. Osteotomy closure is simple with four or five Nice knot osteosutures. The Constant-Murley score and osteotomy healing were assessed at every follow-up. All complications were reviewed.

RESULTS

Forty patients who had a mean age of 63.8 years (range 37-87) at time of surgery and mean follow-up duration of 34 months (range 12-88) were analyzed. Pre-operative Constant-Murley scores improved significantly from 32 ± 19.0 to 58 ± 15.0 (p < 0.001) at one year and 65 ± 13.1 (p < 0.001) at two years. Primary osteotomy healing and callus formation were evident in 95% of cases by three months. Five patients developed post-operative complications (13%) related to the clavicular osteotomy: three mid-diaphyseal clavicular fractures sustained after trauma (8%), one clavicular stress fracture (3%), and case of one loosening (3%). Three patients (8%) required surgical revision of the osteotomy (two internal fixation and one revision osteosuturing). No neurovascular injuries or scapular fractures were encountered.

CONCLUSION

A curved longitudinal clavicular osteotomy is beneficial in difficult revision TSA and is another tool in the arsenal of experienced shoulder surgeons who manage these challenging cases. This surgical technique increases glenoid exposure, facilitates superior dislocation of the humeral component, minimizes anterior deltoid damage, and reduces the risk of neurovascular injuries. All clavicular complications occurred within four months prior to osteotomy union, with many sustained due to trauma. However, patients who developed a complication had comparable shoulder function as those without.

Proximal Humeral Bone Loss in Revision Shoulder Arthroplasty

Proximal humeral bone loss in revision shoulder arthroplasty poses a significant obstacle to achieving stable and reliable fixation of the humeral stem. It is important to identify and classify this bone loss preoperatively, which can range from epiphyseal to substantial diaphyseal bone loss. There are several reconstructive options that can address the varying levels of bone loss, including cemented long-stem fixation, a composite construct using proximal humeral allograft or femoral allograft, proximal humeral endoprosthetic replacement, or total humeral replacement. All of these are viable reconstructive options that have demonstrated adequate to good outcomes.

The router bit extraction technique for removing a well-fixed humeral stem in revision shoulder arthroplasty

Aims

A number of methods have been described to remove a well-fixed humeral implant as part of revision shoulder arthroplasty. These include the use of cortical windows and humeral osteotomies. The router bit extraction technique uses a high-speed router bit to disrupt the bone-implant interface. The implant is then struck in a retrograde fashion with a square-tip impactor and mallet. The purpose of this study was to determine the characteristics and frequency of the different techniques needed for the removal of a well-fixed humeral stem in revision shoulder arthroplasty.

Patients and Methods

Between 2010 and 2018, 288 revision shoulder arthroplasty procedures requiring removal of a well-fixed humeral component were carried out at a tertiary referral centre by a single surgeon. The patient demographics, indications for surgery, and method of extraction were collected.

Results

Of the 288 revisions, 284 humeral stems (98.6%) were removed using the router bit extraction technique alone. Four humeral stems (1.39%) required an additional cortical window. Humeral osteotomy was not necessary in any procedure. Most of the humeral stems removed (78.8%) were cementless. Of the four humeral stems that required a cortical window, three involved removal of a hemiarthroplasty. Two were cemented and two were cementless.

Conclusion

The router bit extraction technique removed a well-fixed humeral component in a very high proportion of patients (98.6%). This method allows surgeons to avoid more invasive approaches involving a cortical window or humeral osteotomy, and their associated complications. Cite this article: Bone Joint J 2019;101-B:1280–1284

Muscle and Joint Function After Anatomic and Reverse Total Shoulder Arthroplasty Using a Modular Shoulder Prosthesis

Changes in joint architecture and muscle loading resulting from total shoulder arthroplasty (TSA) and reverse total shoulder arthroplasty (RSA) are known to influence joint stability and prosthesis survivorship. This study aimed to measure changes in muscle moment arms, muscle lines of action, as well as muscle and joint loading following TSA and RSA using a metal-backed uncemented modular shoulder prosthesis. Eight cadaveric upper extremities were assessed using a customized testing rig. Abduction, flexion, and axial rotation muscle moment arms were quantified using the tendon-excursion method, and muscle line-of-force directions evaluated radiographically pre-operatively, and after TSA and revision RSA. Specimen-specific musculoskeletal models were used to estimate muscle and joint loading pre- and post-operatively. TSA lateralized the glenohumeral joint center by 4.3 ± 3.2 mm, resulting in small but significant increases in middle deltoid force (2.0%BW) and joint compression during flexion (2.1%BW) (p < 0.05). Revision RSA significantly increased the moment arms of the major abductors, flexors, adductors, and extensors, and reduced their peak forces (p < 0.05). The superior inclination of the deltoid significantly increased while the inferior inclination of the rotator cuff muscles decreased (p < 0.05). TSA using an uncemented metal-backed modular shoulder prosthesis effectively restores native joint function; however, lateralization of the glenoid component should be minimized intra-operatively to mitigate increased glenohumeral joint loading and polyethylene liner contact stresses. Revision RSA reduces muscle forces required during shoulder function but produces greater superior joint shear force and less joint compression. The findings may help to guide component selection and placement to mitigate joint instability after arthroplasty. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1988-2003, 2019.

The short-term survival of total stemless shoulder arthroplasty for osteoarthritis is comparable to that of total stemmed shoulder arthroplasty: a Nordic Arthroplasty Register Association study

BACKGROUND

The purpose of this study was to compare the short-term survival rate of total stemless, metaphyseal fixated, shoulder arthroplasty with that of total stemmed shoulder arthroplasty in the treatment of osteoarthritis.

METHODS

Data were collected by the national arthroplasty registries in Denmark, Finland, Norway, and Sweden and merged into 1 dataset under the umbrella of the Nordic Arthroplasty Register Association. For the present study, we included all patients with osteoarthritis treated with either stemless (n = 761) or stemmed (n = 4398) shoulder arthroplasty from 2011 to 2016.

RESULTS

A total of 21 (2.8%) stemless and 116 (2.6%) stemmed shoulder arthroplasties were revised. The 6-year unadjusted cumulative survival rates were 0.953 for stemless shoulder arthroplasty and 0.958 for stemmed shoulder arthroplasty, P = .77. The most common indication for revision of both arthroplasty types was infection. Five (0.7%) stemless and 16 (0.4%) stemmed shoulder arthroplasties were revised because of loosening of either the glenoid or the humeral component. In the multivariate cox regression model, which included age, category, gender, year of surgery, previous surgery, and arthroplasty type, the hazard ratio (HR) for revision of the stemless shoulder arthroplasty was 1.00 (95% confidence interval [CI], 0.63-1.61), P = .99, with the stemmed shoulder arthroplasty as reference. Male gender (HR = 1.50 [95% CI, 1.06-2.13], P = .02) and previous surgery (HR = 2.70 [95% CI, 1.82-4.01], P < .001) were associated with increased risk of revision.

CONCLUSION

The short-term survival of total stemless shoulder arthroplasty appears comparable with total stemmed shoulder arthroplasty, but longer observation time is needed to confirm whether they continue to perform equally.

Revision Reverse Shoulder Arthroplasty

As shoulder arthroplasty becomes increasingly common, the burden of revision shoulder arthroplasty is also increasing. Revision reverse shoulder arthroplasty requires an understanding of the causes of failure and the evaluation of these causes and their sequelae, including infection, instability, component loosening, humeral bone loss, and glenoid bone loss. Revision reverse shoulder arthroplasty is technically complex. On the humeral side, corticotomy may be required for component removal, and bone grafting may be necessary to achieve rotational stability and to restore humeral length and avoid undertensioning and instability. On the glenoid side, bone loss is common, structural bone grafting is not infrequently required, and proper component positioning is required to avoid impingement and component loosening. Although the outcomes are generally inferior to primary reverse total shoulder arthroplasty and complications and revision surgeries are common, revision procedures still lead to notable improvements in pain, motion, and function.

Management of the Failed Arthroplasty for Proximal Humerus Fracture

A variety of reasons exist for failure of arthroplasty performed for management of proximal humerus fracture. Revision surgery for these failures is complex and has a high likelihood of inferior outcomes compared with primary arthroplasty. Successful management requires consideration of various modes of failure including tuberosity malunion or resorption, rotator cuff deficiency, glenoid arthritis, bone loss, component loosening, stiffness, or infection. Although revision to a reverse shoulder arthroplasty is an appealing option to address instability, rotator cuff dysfunction, and glenoid arthritis, there are concerns with higher complication rates and inferior results compared with primary reverse replacement. Any treatment plan should appropriately address the cause for failure to optimize outcomes.

Effects of cemented versus press-fit primary humeral stem fixation in the setting of revision shoulder arthroplasty

BACKGROUND

The influence of primary humeral stem fixation method (cemented or press fit) on intraoperative or postoperative outcomes in the setting of revision shoulder arthroplasty is unknown.

METHODS

A retrospective analysis of a prospectively collected cohort of revision shoulder arthroplasty patients from a single tertiary center was performed. Demographic variables, intraoperative data, and 90-day complication rates were compared between cemented and press-fit primary stem fixation cohorts. Follow-up radiographs were graded and compared using a modified Gruen system for humeral lucencies.

RESULTS

Eighty-six primary shoulder replacements (34 hemiarthroplasties, 39 anatomic total shoulder arthroplasties, 13 reverse total shoulder arthroplasties) underwent revision arthroplasty with humeral stem removal between 2004 and 2017. Forty-five patients had cemented primary humeral fixation and 41 had press-fit fixation. The cemented cohort was older than the cementless cohort (66.6 vs. 61.4 years; P = .03) but otherwise demonstrated no difference in gender, body mass index, type of primary prosthesis (hemi, total, or reverse), or time between primary and revision operations. The cemented and cementless cohorts showed similar rates of humeral osteotomy (28.9% vs. 29.3%; P = .97), operative time (133.5  vs. 121.3 minutes; P = .16), and 90-day complication rates (13.3% vs. 9.8%; P = .61). Cemented vs. press-fit primary stems also had similar rates of humeral lucencies seen on follow-up radiographs after revision (77.1% vs. 60.6%; P = .14).

CONCLUSION

Humeral stem fixation with or without cement during primary shoulder arthroplasty demonstrated similar operative time, need for intraoperative humeral osteotomy, and postoperative complication rates in the setting of revision arthroplasty.

Short-term clinical outcome of an anatomic short-stem humeral component in total shoulder arthroplasty

BACKGROUND

Short-stem press-fit humeral components have recently been developed in an effort to preserve bone in total shoulder arthroplasty (TSA), but few studies have reported outcomes of these devices. The purpose of this study was to evaluate the short-term clinical outcomes of an anatomic short-stem humeral component in TSA. We hypothesized that the implant would lead to significant functional improvement with low rates of radiographic loosening.

METHODS

A multicenter retrospective review was performed of TSAs using an anatomic short-stem humeral component (Apex; Arthrex, Inc., Naples, FL, USA). The minimum follow-up was 2 years. Functional outcome was evaluated according to the American Shoulder and Elbow Surgeons score, Visual Analog Scale for pain, Single Assessment Numeric Evaluation, Simple Shoulder Test, and range of motion. A radiographic analysis was performed to evaluate component loosening.

RESULTS

Sixty-four patients with a mean age of 64.1 years were available for follow-up at a mean of 25 months postoperatively. There were significant improvements in the Visual Analog Scale (6 to 2; P < .001), Simple Shoulder Test (4 to 10; P < .001), Single Assessment Numeric Evaluation (32 to 84; P < .001), and American Shoulder and Elbow Surgeons (37 to 80; P < .001) scores. Forward flexion improved from 116° to 148° (P < .001), external rotation improved from 30° to 57° (P < .001), and internal rotation improved from an average spinal level of S1 to L2 (P < .001). On radiographic examination, 9% of stems were deemed at risk for loosening, but there was no gross loosening in any patient.

CONCLUSIONS

TSA with an anatomic press-fit short-stem humeral component is associated with significant improvements in clinical outcomes, without evidence of component loosening at short-term follow-up.

Surgical anatomy of the radial nerve in the deltopectoral approach for revision shoulder arthroplasty and periprosthetic fracture fixation: a cadaveric study

BACKGROUND

Radial nerve injury is a rare but clinically significant complication of revision shoulder arthroplasty and fixation of native and periprosthetic proximal humeral fractures. Understanding of the anatomic relationship between the radial nerve as it enters the humeral spiral groove and anterior shoulder landmarks in a deltopectoral approach is necessary to avoid iatrogenic radial nerve injury.

METHODS

Eight forequarter cadaveric specimens were dissected through a deltopectoral approach. Distances between the radial nerve entry into the proximal spiral groove and the coracoid process, distal lesser tuberosity/inferior subscapularis insertion, superior latissimus insertion, and inferior latissimus insertion were measured. Means, standard deviations, and ranges were determined for each distance.

RESULTS

The radial nerve entry into the proximal spiral groove averaged 133.1 mm (range, 110.3-153.0 mm) from the coracoid process, 101.9 mm (range, 76.5-124.3 mm) from the distal lesser tuberosity/inferior subscapularis insertion, 81.0 mm (range, 63.4-101.5 mm) from the superior latissimus insertion, and 39.6 mm (range, 25.5-55.4 mm) from the inferior latissimus insertion. The proximal spiral groove was distal to the inferior latissimus insertion in all specimens.

CONCLUSION

The risk of iatrogenic injury to the radial nerve at the spiral groove may be minimized through proper identification and protection or avoidance of circumferential fixation. However, if encircling fixation with cerclage cables is necessary, instrumentation proximal to the inferior edge of the latissimus dorsi insertion may reduce the risk of radial nerve injury.

Nine-year outcome after anatomic stemless shoulder prosthesis: clinical and radiologic results

BACKGROUND

Several stemless shoulder implants are available on the market, but only a few studies have presented results with sufficient mid- to long-term follow-up. The present study evaluated clinical and radiologic outcomes 9 years after anatomic stemless shoulder replacement.

METHODS

This is a prospective cohort study evaluating the stemless shoulder prosthesis since 2005. Anatomic stemless shoulder replacement using a single prosthesis was performed in 49 shoulders; 17 underwent total shoulder replacement, and 32 underwent hemiarthroplasty. Forty-three patients were clinically and radiologically monitored after a mean of 9 years (range, 90-127 months; follow-up rate, 88%). The indications for shoulder replacement were primary osteoarthritis in 7 shoulders, post-traumatic in 24, instability in 7, cuff tear arthropathy in 2, postinfectious arthritis in 1, and revision arthroplasty in 2.

RESULTS

The Constant-Murley Score improved significantly from 52% to 79% (P < .0001). The active range of motion also increased significantly for flexion from 101° to 118° (P = .022), for abduction from 79° to 105° (P = .02), and for external rotation from 21° to 43° (P < .0001). Radiologic evaluation revealed incomplete radiolucency in 1 patient without clinical significance or further intervention. No revision caused by loosening or countersinking of the humeral implant was observed.

CONCLUSIONS

The 9-year outcome after stemless shoulder replacement is comparable to that of third- and fourth-generation standard shoulder arthroplasty.

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

BACKGROUND

When fixed with bone ingrowth, a tight diaphyseal press fit, or cement, the humeral component of a shoulder arthroplasty may present problems of malposition, stress shielding, or periprosthetic fracture or difficulty with removal at revision arthroplasty. We have avoided the need for these fixation methods by using impaction cancellous autografting of the humeral stem, minimizing contact between the prosthetic stem and the humeral cortex. This study presents the radiographic survivorship of impaction-autografted humeral implants using component subsidence as the primary endpoint.

METHODS

We reviewed 286 primary anatomic shoulder arthroplasties having an average follow-up of 4.9 ± 2.7 years. Initial postoperative radiographs and minimum 2-year follow-up radiographs were evaluated by 3 observers to assess subsidence.

RESULTS

Two different implants (Humeral Replacement Prosthesis [HRP] and Global Advantage prosthesis) were used. Of 286 stems, 267 (93.4%) had not subsided. The Global Advantage prosthesis had a subsidence-free survival rate of 98.5% at 5 years. The stiffer-stemmed HRP used early during the study had a higher rate of subsidence compared with the currently used Global Advantage stem (hazard ratio, 5.6; P = .001). Radiolucent lines of 2 mm or greater were less common for the Global Advantage prosthesis than for the HRP in each of 7 zones (P < .001). Total shoulder arthroplasty was associated with a higher rate of subsidence compared with hemiarthroplasty (hazard ratio, 2.6; P = .12).

CONCLUSIONS

Impaction autografting provides a secure, durable, bone-preserving means of humeral component fixation in anatomic shoulder arthroplasty.

Revision shoulder arthroplasty: does the stem really matter?

BACKGROUND

The management of a failed shoulder arthroplasty represents a complex and difficult problem for the treating surgeon, with potential difficulties and complications that are related to the need to remove a well-fixed stem. The aim of this study is to compare the intraoperative complications, postoperative complications, and outcome of revisions from stemmed arthroplasties (STAs) with those from surface replacement arthroplasties (SRAs).

METHODS

From 2005 to 2012, 40 consecutive revision shoulder arthroplasties were performed at our institute: 17 from STAs and 23 from SRAs. Perioperative events, operation time, blood loss, intraoperative fractures, and use of structural allograft were recorded. Clinical and radiologic outcomes were analyzed.

RESULTS

Operation time, need for humeral osteotomy, need for structural allograft, and number of intraoperative fractures were significantly higher in the STA group. Blood loss, drop in hemoglobin level, need for blood transfusion, and hospitalization time were also higher in the STA group, but these differences were not statistically significant. Reoperation was performed in 3 patients in the SRA group. A significant clinical improvement was observed in both groups. The Constant score was higher in the SRA group.

CONCLUSION

Revision of STAs is a more demanding procedure. The postoperative complication rate was slightly higher in the SRA group. The group with revision of SRAs showed slightly better clinical and radiographic results, but there was no statistically significant difference between the groups.

Clinical and Radiographic Outcomes of the Simpliciti Canal-Sparing Shoulder Arthroplasty System: A Prospective Two-Year Multicenter Study

BACKGROUND

Stemmed humeral components have been used since the 1950s; canal-sparing (also known as stemless) humeral components became commercially available in Europe in 2004. The Simpliciti total shoulder system (Wright Medical, formerly Tornier) is a press-fit, porous-coated, canal-sparing humeral implant that relies on metaphyseal fixation only. This prospective, single-arm, multicenter study was performed to evaluate the two-year clinical and radiographic results of the Simpliciti prosthesis in the U.S.

METHODS

One hundred and fifty-seven patients with glenohumeral arthritis were enrolled at fourteen U.S. sites between July 2011 and November 2012 in a U.S. Food and Drug Administration (FDA) Investigational Device Exemption (IDE)-approved protocol. Their range of motion, strength, pain level, Constant score, Simple Shoulder Test (SST) score, and American Shoulder and Elbow Surgeons (ASES) score were compared between the preoperative and two-year postoperative evaluations. Statistical analyses were performed with the Student t test with 95% confidence intervals. Radiographic evaluation was performed at two weeks and one and two years postoperatively.

RESULTS

One hundred and forty-nine of the 157 patients were followed for a minimum of two years. The mean age and sex-adjusted Constant, SST, and ASES scores improved from 56% preoperatively to 104% at two years (p < 0.0001), from 4 points preoperatively to 11 points at two years (p < 0.0001), and from 38 points preoperatively to 92 points at two years (p < 0.0001), respectively. The mean forward elevation improved from 103° ± 27° to 147° ± 24° (p < 0.0001) and the mean external rotation, from 31° ± 20° to 56° ± 15° (p < 0.0001). The mean strength in elevation, as recorded with a dynamometer, improved from 12.5 to 15.7 lb (5.7 to 7.1 kg) (p < 0.0001), and the mean pain level, as measured with a visual analog scale, decreased from 5.9 to 0.5 (p < 0.0001). There were three postoperative complications that resulted in revision surgery: infection, glenoid component loosening, and failure of a subscapularis repair. There was no evidence of migration, subsidence, osteolysis, or loosening of the humeral components or surviving glenoid components.

CONCLUSIONS

The study demonstrated good results at a minimum of two years following use of the Simpliciti canal-sparing humeral component. Clinical results including the range of motion and the Constant, SST, and ASES scores improved significantly, and radiographic analysis showed no signs of loosening, osteolysis, or subsidence of the humeral components or surviving glenoid components.

LEVEL OF EVIDENCE

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

Stemless shoulder arthroplasty-current results and designs

Stemless shoulder arthroplasty was originally introduced in 2004 by a single manufacturer. Now, over a decade later, numerous designs are available outside the USA, but as yet, only one implant has been cleared by the Food and Drug Administration (FDA) and is available for use within the USA. Often referred to as "canal sparing," these implants are designed for metaphyseal fixation to minimize humeral bone removal, avoid intraoperative and postoperative humeral fracture complications, and to decrease morbidity associated with revision operations. Recently, the second generation of stemless arthroplasty, a convertible implant allowing use in either anatomic or reverse arthroplasty configuration, was released for use outside the USA. This paper will review the available designs, reported results, and raise potential concerns for this emerging technology.

Management of complications after revision shoulder arthroplasty

Complications after revision shoulder arthroplasty are similar to those in the primary setting which include instability, fracture, bone loss, infection, nerve injury, and loosening. Unlike in the primary setting, however, the rate of complications for revisions is significantly greater and the management is more complex because of overlapping complications and limited treatment options. Furthermore, there is a paucity of evidence-based literature to direct the management options in these patients. The purposes of this review are to broadly outline the major complications that are seen in revision shoulder arthroplasty and to provide general principles on how to recognize and approach these complex cases.

Humeral windows and longitudinal splits for component removal in revision shoulder arthroplasty

BACKGROUND

Removal of a humeral component during revision shoulder arthroplasty can be difficult. If the component cannot be extracted from above, an alternative approach may compromise bone integrity. Two potential solutions are a humeral window and a longitudinal split. This review was performed to determine complications and outcomes associated with these osteotomies during revision arthroplasty.

METHODS

We reviewed records of 427 patients undergoing revision shoulder arthroplasty, identifying those requiring a window or longitudinal split. Outcomes were intraoperative and postoperative complications, rate of healing, and security of implant fixation.

RESULTS

Twenty-six patients underwent creation of a window. Six intraoperative fractures were documented: 5 in greater tuberosity and 1 in humeral shaft. At radiographic follow-up, 23 of 26 windows healed; 2 patients had limited follow-up, and 1 did not have follow-up at our institution. Nineteen patients underwent longitudinal osteotomy. One had intraoperative fracture in greater tuberosity. At radiographic follow-up, 17 of 19 longitudinal splits healed; 1 had limited radiographic follow-up, and 1 did not have follow-up at our institution. Three patients underwent formation of both window and longitudinal osteotomy. At radiographic follow-up, all shoulders healed, and there were no intraoperative or postoperative fractures or malunions.

CONCLUSIONS

In both groups, there were no cases of malunion or clinical loosening. These data suggest that windows and longitudinal splits facilitate controlled removal of well-fixed components with high rate of union and low rate of intraoperative or postoperative sequelae.

Stainless steel wire versus FiberWire suture cerclage fixation to stabilize the humerus in total shoulder arthroplasty

HYPOTHESIS

No. 5 FiberWire (Arthrex, Naples, FL, USA) cerclage (FWC) and 1.25-mm stainless steel wire cerclage (SSWC) are biomechanically similar in resistance to prosthetic subsidence in shoulder arthroplasty.

METHODS

In this laboratory bench study, 3 different surgical knot configurations (4-throw knot, cow hitch, and simple hitch) using a No. 5 FWC were evaluated and compared with a 1.25-mm SSWC. First, distraction tests were performed using bovine femoral cortical half shells mounted on a testing jig. Cerclage tightening, load to a 3-mm gap opening, and load to total failure were measured. Second, uncemented humeral prosthetic stems were inserted into an experimentally split humeral medullary canal, secured by the cerclage. After 100 N of preloading, the prosthesis was advanced into the humerus at a speed of 0.2 mm/s, and resistance during subsidence up to a penetration depth of 10 mm, as well as gap opening, was measured.

RESULTS

Tightening force showed higher values for SSWC (618 N) than FWC (131-137 N) (P < .001). Load to total failure was comparable among the 3 different FWC knots (2,642-2,804 N), which were significantly stronger than SSWC (1,775 N, P < .001). At 3 mm of distraction, SSWC (1,820 N), cow hitch (1,803 N), and single-throw hitch (1,709 N) performed significantly better than a 4-throw knot (1,289 N) (P < .01). Subsidence testing showed no difference in force restraint or gap opening between the best FWC and SSWC.

CONCLUSIONS

FWCs appear, in vitro, equally suitable to steel wires to stabilize nondisplaced periprosthetic humeral fractures. To actively reduce a displaced fracture, steel wires may still be the first choice.

Increased-offset reverse shoulder arthroplasty for the treatment of failed post-traumatic humeral head replacement

BACKGROUND

Late complications after humeral head replacement (HHR) for comminuted proximal humeral fractures are common and may necessitate revision surgery. This study evaluated the outcome of revision surgery of failed post-traumatic HHR with a less medialized reverse shoulder prosthesis.

METHODS

Thirty-three patients with failed post-traumatic HHR due to rotator-cuff insufficiency and glenoid erosion, but with sufficient preservation of the glenoid bone stock to permit primary stability of an inverted glenoid implant, underwent revision using the Bayley-Walker reverse shoulder prosthesis (Stanmore Implants, Elstree, UK) and were monitored up for a mean of 31 months. Outcome measures included the Oxford Shoulder Score, subjective shoulder value, pain rating, active range of motion, and shoulder radiographs.

RESULTS

The average postrevision Oxford Shoulder Score and subjective shoulder value improved from 50 ± 6 to 29 ± 11 and from 23 ± 19 to 51 ± 23, respectively (P < .001). Pain level decreased from 6.2 ± 2.1 to 1.4 ± 2.0 (P < .001). Active forward flexion increased from 34° ± 22° to 63° ± 30° and external rotation from 11° ± 14° to 20° ± 16°(P < .01). More patients were able to use their affected arm to reach a functional triangle consisting the mouth, opposite armpit, and ipsilateral buttock after revision (24% vs 73%; P < .001). Seven patients (21%) had postrevision complications. No glenoid loosening or scapular notching occurred.

CONCLUSION

Revision of failed post-traumatic HHR with the Bayley-Walker shoulder offers reliable pain relief and improvement in shoulder function with a complication rate similar to other reverse prostheses. Nevertheless, revision shoulder arthroplasty remains challenging with a high rate of complications.

Revision arthroplasty with a hip-inspired computer-assisted design/computer-assisted manufacturing implant for glenoid-deficient shoulders

BACKGROUND

Revision arthroplasty for failed post-traumatic humeral head replacement associated with rotator cuff and glenoid deficiency is challenging. Current surgical solutions are fraught with complications, and no best-practice strategy has been established. We hypothesized that the computer-assisted design/computer-assisted manufacturing (CAD/CAM) shoulder (Stanmore Implants, Elstree, UK), a total shoulder design resembling a total hip prosthesis, can offer a reliable alternative in this surgically challenging subset of patients with rotator cuff deficiency and advanced glenoid bone loss.

METHODS

Twenty-one patients with failed post-traumatic humeral head replacement associated with rotator cuff and glenoid deficiency underwent revision with CAD/CAM shoulders between 2005 and 2010. Clinical data were collected prospectively and analyzed at a mean follow-up of 3 years.

RESULTS

After revision, the pain rating at rest (on a 0-10 numerical scale) decreased from 5.6 ± 1.3 to 1.1 ± 1.3 (P < .001) and pain during activity decreased from 7.4 ± 1.2 to 2.1 ± 1.8 (P < .001). The Oxford shoulder score improved from 47 ± 6 to 31 ± 9 (P < .001), and the subjective shoulder value (on a 0%-100% scale) improved from 22% ± 14% to 45% ± 18% (P < .001). Active shoulder range of motion was similar before and after revision. Postoperative complications occurred in 9 patients and included 1 infection, 2 periprosthetic fractures, 2 prosthetic dislocations, and 4 fixation screw fractures. No case of glenoid loosening occurred.

CONCLUSION

The CAD/CAM shoulder offers a reliable method of securing a glenoid component in shoulders with advanced glenoid deficiency and should be considered as an alternative to other surgical methods in these challenging cases. At 3 years' follow-up, pain and clinical scores improved significantly and no case of glenoid loosening occurred.

Conversion of shoulder arthroplasty to reverse implants: clinical and radiological results using a modular system

PURPOSE

Revision of a shoulder arthroplasty to a reverse arthroplasty is a highly demanding procedure. The aim of this study is to report the clinical results of hemi and total shoulder prosthesis revisions to reverse implants without removal of the humeral stem, using a modular shoulder replacement system (SMR Lima LTD). We retrospectively reviewed 26 patients who underwent an operation from 2004 to 2009.

METHODS

The patients were divided into two groups: in Group I, 18 patients underwent a revision of hemiarthroplasty implanted for fracture; in Group II, eight patients underwent a revision of anatomical total prosthesis. All patients were evaluated at a mean follow-up of 32.3 (±12.7) months using the Constant score rating scale and by range of motion evaluation, EQ-VAS, X-ray and CT scan.

RESULTS

The Constant score of each patient was 47.88 (±5.88) after the revision. The EQ-VAS improved from 40 (±20) to 70 (±10). All patients improved in terms of range of motion. The radiographs and CT scans obtained after revision showed good integration and no signs of loosening of the implant. The mean time of surgery was recorded as 62' (±8'), with a maximum blood loss of less than 300 ml in all cases.

CONCLUSIONS

Our study demonstrates that using a full modular system at the time of the first implant allows avoidance of the step to remove the humeral stem and metal back in cases of shoulder prosthesis revision to a reverse prosthesis, resulting in a short operative time, few intraoperative complications and a satisfactory clinical outcome at medium-term follow-up.

Revision of total shoulder arthroplasty

In France, the number of revisions for total shoulder arthroplasty (TSA) has increased by 29% between 2006 and 2010. Published studies have reported a revision rate of approximately 11% for hemi-arthroplasty and total anatomical implants, and 10% for reversed implants. The decision to revise or not revise a TSA requires that a rigorous, clinical, laboratory and imaging initial assessment be done in order to answer five questions. Is it infected? Is it unstable? Is it worn? Is it loosened? How is the rotator cuff? This assessment and an evaluation of the bone stock are required to decide whether or not to revise. If the problem is infection, the best solution is not always complete removal of the implant, which results in very poor shoulder function. In such a situation, a multidisciplinary consultation is essential in the decision-making. If the problem is instability, the cause must be identified and rectified. Instability is often caused by insufficient restoration of the humerus length. If the problem is loosening, the type of revision must take into account the patient's age, the rotator cuff status and the available bone stock. The possibilities to reimplant an anatomical glenoid are scarce, and only for cases with minor bone loss and an intact cuff. If a bone graft without reimplantation of a glenoid component is preferred, it should be a tricortical graft to resist wear and medialisation. In the other cases, a reversed shoulder implant with an autograft is preferable. Whether or not the humeral stem is loose, it must often be removed. However, its removal is very difficult, risky and it often causes complications, with humerus fracture being the most common. The possibility of reconstruction depends on the quality of the remaining bone stock. In all these risky situations, the patient should be duly informed and should take part in the decision-making process.