Proximal humeral replacement using a fixed-fulcrum endoprosthesis

Poor clinical outcomes and high rates of dislocation after modular reverse shoulder arthroplasty for proximal humeral oncologic resection

PURPOSE

The shoulder is the most common site for upper extremity tumors. The aim of the study was to analyze the outcomes and the complications of modular reverse shoulder arthroplasty (RSA) after proximal humerus resection.

METHODS

We retrospectively included 15 consecutive patients who underwent a modular MUTARS™ RSA reconstruction after proximal humerus tumour resection between 2017 and 2020. The mean age was 52 years. Their clinical outcomes were assessed using the Constant-Murley score and the MSTS shoulder. Radiological outcomes were assessed based on the presence of loosening, osteolysis, and scapular notching. Complications such as dislocation, oncological recurrence, and infection were assessed. Mean follow-up time was 32.9 months (24 to 45).

RESULTS

The mean adjusted Constant score was 50.7% (min 22, max 81), and the mean MSTS score was 15.6 (min 4, max 26). We had no loosening, osteolysis, or scapular notching on the radiographs at last follow-up. We had a high complication rate of 53%: one infection, one oncological recurrence, and six dislocations (40%), of which five were re-operated.

CONCLUSION

In our experience, the MUTARS™ Implantcast™ modular RSA has poor functional results and a high rate of dislocation in the case of large proximal humerus resections below the distal insertion of the deltoid.

Postoperative Outcomes of Total Humerus Replacement for Oncologic Reconstruction of the Upper Limb: A Systematic Review of the Literature

BACKGROUND

Total humerus replacement (THR) is a reconstruction procedure performed after resection of massive humeral tumors. However, there is limited literature on the rates of failure and functional outcomes of this implant. Our study aimed to determine the main failure modes, implant survival, and postoperative functional outcomes of THR.

METHODS

A comprehensive search of the PubMed and Embase databases was conducted. We registered our study on PROSPERO (448684) and used the Strengthening the Reporting of Observational Studies in Epidemiology checklist for quality assessment. The Henderson classification was used to assess endoprosthesis failure and the Musculoskeletal Tumor Society (MSTS) score for functional outcomes. Weighted means and standard deviations were calculated.

RESULTS

Ten studies comprising 171 patients undergoing THR were finally included. The overall failure rate was 32.2%. Tumor progression (12.6%) and prosthetic infections (9.4%) were the most common failure modes, followed by soft-tissue failures (5.9%), aseptic loosening (3.5%), and structural failure (1.8%). Two-year, 5-year, and 10-year implant survival rates for the entire cohort were 86%, 81%, and 69.3%. Ten-year implant survival for primary THRs was 78.3%, compared with 38.6% for revision THRs (p = 0.049). The mean MSTS score at the last follow-up was 77%. Patients whose implants did not fail had a higher MSTS score (79.3%) than those with failed implants (71.4%) (p = 0.02).

CONCLUSION

One-third of THR will fail, mostly due to tumor progression and prosthetic infection. Overall functional scores were acceptable, with MSTS scores displaying great hand and elbow function but limited shoulder function.

LEVEL OF EVIDENCE

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

Proximal Humerus Reconstruction for Bone Sarcomas: A Critical Analysis

» The proximal humerus is a common location for primary bone tumors, and the goal of surgical care is to obtain a negative margin resection and subsequent reconstruction of the proximal humerus to allow for shoulder function.» The current evidence supports the use of reverse total shoulder arthroplasty over hemiarthroplasty when reconstructing the proximal humerus after resection of a bone sarcoma if the axillary nerve can be preserved.» There is a lack of high-quality data comparing allograft prosthetic composite (APC) with endoprosthetic reconstruction of the proximal humerus.» Reverse APC should be performed using an allograft with donor rotator cuff to allow for soft-tissue repair of the donor and host rotator cuff, leading to improvements in shoulder motion compared with an endoprosthesis.

Functional outcome and quality of life following resection of the proximal humerus performed for musculoskeletal tumors and reconstruction done by four different methods

INTRODUCTION

The proximal humerus is a frequent site for both primary and secondary bone tumors. Several options are currently available to reconstruct the resected humerus, but there is no consensus regarding optimal reconstruction. The aim of this retrospective study was to compare the functional outcome, complications and patient compliance following four different types of reconstructive techniques.

MATERIAL AND METHODS

The authors performed 90 proximal humerus resections due to primary and secondary bone tumors over the past 21 years. Four different procedures were performed for reconstruction following the resection: fibula autograft transplantation, osteoarticular allograft implantation, modular tumor endoprosthesis (hemiarthroplasty) and reconstruction of the defect with a reverse shoulder prosthesis-allograft composite. A retrospective analysis of the complications and patient's physical status was performed. Functional outcome and life quality was evaluated by using the MSTS and SF-36 scores.

RESULTS

The best range of motion was observed following arthroplasty with a reverse shoulder prosthesis-homograft composite followed by a fibula autograft reconstruction. Revision surgery was required due to major complications most frequently in the osteoarticular allograft group, followed by the reverse shoulder prosthesis-allograft composite group, the autologous fibula transplantation group; the tumor endoprosthesis hemiarthroplasty group had superior results regarding revision surgery (40, 25, 24 and 14% respectively). MSTS was 84% on average for the reverse shoulder prosthesis-allograft composite group, 70% for the autologous fibula group, 67% for the anatomical hemiarthroplasty group and 64% for the osteoartricular allograft group. Using the SF-36 questionnaire for assessment no significant differences were found between the four groups regarding quality of life.

DISCUSSION

Based on the results of our study the best functional performance (range of motion and patient compliance) was achieved in the a reverse prosthesis-allograft combination group-in cases where the axillary nerve could be spared. The use of an osteoarticular allograft resulted in unsatisfying functional results and high complication rates, therefore we do not recommend it as a reconstructive method following resection of the proximal humerus due to either primary or metastatic bone tumors. Young patients who have good life expectancy but a small humerus or intramedullar cavity reconstruction by implantation of a fibula autograft is a good option. For patients with a poor prognosis (i.g. bone metastases) or in cases where the axillary nerve must be sacrificed, hemiarthroplasty using a tumor endoprosthesis was found to have acceptable results with a low complication rate. According to the MSTS and SF-36 functional scoring systems patients compliance was nearly identical following all four types of reconstruction techniques; the underlying cause may be the complexity of the shoulder girdle. However, we recommend the implantation of a reverse shoulder prosthesis-allograft whenever indication is appropriate, as it has been demonstrated to provide excellent functional outcomes, especially in young adults.

Anatomical and reverse megaprosthesis in proximal humerus reconstructions after oncologic resections: a systematic review and meta-analysis

AIM

Anatomic (AN) Endoprosthesis (EPR) reconstructions of the shoulder after intra-articular proximal humerus (Malawer type 1) resections are characterized by early recovery and low complications rate. However, shoulder instability and limited mobility can occur. Reverse shoulder (RS) EPR has been introduced to improve functional outcome. The aim of this systematic review is to evaluate shoulder reconstructions with AN or RS EPR after Malawer type 1 resection, comparing complications and functional results.

METHODS

Through an electronic systematic search of PubMed, articles concerning EPR after shoulder Malawer type 1 resections were reviewed. Complications rate, range of motion (ROM) and functional outcome (Musculoskeletal Society Tumor Society-MSTS score) of AN and RS EPR were evaluated.

RESULTS

Sixteen studies were included. A similar complication rate was observed between AN and RS EPR rate (26.4% and 22.4%, respectively, p = 0.37). Soft tissue failure was the most frequent complication and cause of revision in both groups. Mean post-operative flexion and abduction ROM and MSTS scores were significantly higher in RS EPR, particularly among patients with preserved deltoid function (p = 0.013, p = 0.025 and p = 0.005, respectively).

CONCLUSIONS

Anatomic and reverse shoulder EPR represent safe and effective implants for shoulder reconstruction, with similar implant stability and complication rates. RS EPR significantly improves post-operative ROM and functional outcomes, especially when at least a partial function of the abductor apparatus is preserved.

Efficacy and safety of a 3D-printed arthrodesis prosthesis for reconstruction after resection of the proximal humerus: preliminary outcomes with a minimum 2-year follow-up

Background

The purpose of this study was to investigate the feasibility of using a three-dimensional (3D)-printed arthrodesis prosthesis for reconstruction of the proximal humeral defect after tumor resection.

Methods

A novel proximal humeral prosthesis was designed to restore bone continuity and shoulder arthrodesis and was fabricated via 3D printing technology. Ten patients with primary malignancies in the proximal humerus underwent intra-articular resection and replacement with this prosthesis from 2017 to 2019. Baseline and operative data, oncological and prosthetic survival, and functional status were summarized.

Results

This cohort consisted of 9 males and 1 female with a mean age of 32.1 ± 16.1 years. Diagnoses included 5 cases of osteosarcoma, 3 cases of chondrosarcoma and 1 each case of undifferentiated pleomorphic sarcoma and malignant myoepithelioma. The mean operative duration, intraoperative hemorrhage and postoperative length of hospitalization were 151.5 ± 61.0 min, 410.0 ± 353.4 ml and 5.3 ± 1.9 d, respectively. The mean follow-up duration was 29.3 ± 6.4 months, with a minimum of 24 months for the surviving patients. Two patients experienced local recurrence, and four patients developed distant metastases. Detachment of the taper occurred in two patients. One was managed conservatively, and the other received amputation due to concurrent tumor recurrence. The mean MSTS-93 and ASES scores and ranges of forwards flexion and abduction were 24.9 ± 3.1, 79.4 ± 8.3, 71.3 ± 19.4°, and 61.3 ± 16.4°, respectively. The functional outcomes were independent of the preservation of the axillary nerve. Histological study of the glenoid component showed evidence of bone ingrowth at the bone-prosthesis porous interface.

Conclusion

Application of the 3D-printed arthrodesis prosthesis might be a safe and efficacious method for functional reconstruction in patients who underwent resection of the proximal humerus, especially for those without preservation of the axillary nerve.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05581-6.

Reverse shoulder megaprosthesis replacement for aggressive aneurysm bone cyst of proximal humerus: Case report and literature review

INTRODUCTION

and importance: Wide resection in the surgical treatment of aneurysms bone cysts is often performed in cases where the tumor is large, recurrent, growing, and intensely invasive. Reshaping the defect after tumor removal is a necessary issue to restore shape and maintain function for the patient.

CASE PRESENTATION

A 26-year-old male patient, diagnosed with an aneurysm bone cyst in the proximal humerus, underwent surgery for curettage and bone grafting twice. After surgery, there was still pain in the shoulder area, the tumor progressed aggressively with limited shoulder movement. Based on the imaging re-evaluation, it was shown that the tumor increased rapidly in size, invaded the soft tissue, and completely changed the normal structure of the shoulder joint, and the proximal humerus. We used a reverse shoulder joint with an additional module to restore the bone defect of the tumor and the function of the shoulder joint. Follows-up showed that patient no longer pain in shoulder area, shoulder joint function recovery is progressing well, Musculoskeletal Tumor Society (MSTS) score is 25 & 28, shoulder joint function score according to ASES scale: 80 & 93.33 respectively at 3 months and 6 months after surgery.

CLINICAL DISCUSSION

Aggresive aneurysm bone cyst of proximal humerus is not common and still a challenge to the treatment. Due to the bone and joint destruction, the indication of tumor resection and reconstruct the joint and bone loss is required. Among several solution, reverse shoulder megaprosthesis is a newest one can favor the purpose of our treatment. Up to now, this solution is mainly used to preserving for malignant bone tumor.

CONCLUSIONS

Tumor wide resection with modular reverse shoulder replacement with the modular segment is a reasonable intervention option in cases of large aneurysm bone cysts, with rapid recurrence, aggressive progression, and soft tissue invasion.

Reverse total shoulder arthroplasty for oncologic reconstruction of the proximal humerus: a systematic review

BACKGROUND

In recent years, there has been growing interest in the use of reverse total shoulder arthroplasty (rTSA) for reconstruction of the proximal humerus after oncologic resection. However, the indications and outcomes of oncologic rTSA remain unclear.

METHODS

We conducted a systematic review to identify studies that reported outcomes of patients who underwent rTSA for oncologic reconstruction of the proximal humerus. Extracted data included demographic characteristics, indications, operative techniques, outcomes, and complications. Weighted means were calculated according to sample size.

RESULTS

Twelve studies were included, containing 194 patients who underwent rTSA for oncologic reconstruction of the proximal humerus. The mean patient age was 48 years, and 52% of patients were male. Primary malignancies were present in 55% of patients; metastatic disease, 30%; and benign tumors, 9%. The mean humeral resection length was 12 cm. The mean postoperative Musculoskeletal Tumor Society score was 78%; Constant score, 60; and Toronto Extremity Salvage Score, 77%. The mean complication rate was 28%, with shoulder instability accounting for 63% of complications. Revisions were performed in 16% of patients, and the mean implant survival rate was 89% at a mean follow-up across studies of 53 months.

CONCLUSIONS

Although the existing literature is of poor study quality, with a high level of heterogeneity and risk of bias, rTSA appears to be a suitable option in appropriately selected patients undergoing oncologic resection and reconstruction of the proximal humerus. The most common complication is instability. Higher-quality evidence is needed to help guide decision making on appropriate implant utilization for patients undergoing oncologic resection of the proximal humerus.

Management of Humeral and Glenoid Bone Defects in Reverse Shoulder Arthroplasty

Bone loss of either the glenoid or the humerus is a challenging problem in reverse total shoulder arthroplasty. When left unaddressed, it can lead to early failure of the implant and poor outcomes. Humeral bone loss can be addressed with the use of an endoprosthesis or allograft prosthetic implant. Glenoid bone loss can be treated with a variety of grafting options, such as augmented implants, patient-specific navigation, and implantation systems.

Proximal Humerus Reconstruction after Tumor Resection: An Overview of Surgical Management

Proximal humerus is one of the anatomical sites that are most frequently involved by bone and soft tissue malignant tumors. Alone or in association with adjuvant treatments, surgery represents the main therapeutic option to treat and eradicate these diseases. Once the first-line option, in the last decades, amputation lost its role as treatment of choice for the large majority of cases in favor of the modern limb sparing surgery that promises to preserve anatomy and-as much as possible-upper limb functionality. Currently, the main approaches used to replace proximal humerus after a wide resection in oncologic surgery can be summarized in biological reconstructions (allografts and autografts), prosthetic reconstructions (anatomic endoprostheses, total reverse shoulder prostheses), and graft-prosthetic composite reconstructions. The purpose of this overview is to present nowadays surgical options for proximal humerus reconstruction in oncological patients, with their respective advantages and disadvantages.

Custom Prosthetic Reconstruction for Severe Proximal Humeral Bone Loss Status Post Infected Arthroplasty: A Case Report

CASE

A 68-year-old male, status post revision right reverse total shoulder arthroplasty (RTSA) for periprosthetic fracture, suffered a periprosthetic joint infection necessitating 2-stage revision. Imaging revealed 8.6 cm of ipsilateral proximal humeral bone loss (PHBL) including loss of the greater and lesser tuberosities. A 2-stage revision was performed using an antibiotic spacer, followed by a custom long-stem RTSA for definitive reconstruction. Two years postoperatively, the patient had significantly improved pain and functional range of motion.

CONCLUSION

Custom long-stem RTSA could serve as a potentially viable reconstructive option in patients with severe PHBL.

Mesh patch and anchors can improve clinical results of prosthetic replacement after resection of primary proximal humerus malignant tumor

The purpose of this study was to evaluate the functional results, complications and related factors of prosthesis reconstruction after malignant tumor resection of primary proximal humeral, and also evaluate whether soft tissue reconstruction with mesh patch and anchors can improve clinical results. From 2002 to 2016, forty-one patients were enrolled in this study. The pathological diagnosis contained 27 cases of osteosarcoma, 7 cases of chondrosarcoma and other primary malignant bone tumors. Both mesh patch and anchors were used in the reconstruction of joint capsule and the surrounding soft tissues in 27 cases. The mean postoperative follow-up was 60.6 months. The average active abduction angle and passive abduction angle was 33.5 (5–71) degrees and 72.4 (52–104) degrees. The prosthetic humeral head displacement was over 2 cm in 5 cases (12.2%). The average MSTS score was 23.1. The overall 5-year survival rate of prosthesis was 88.2%. The length of osteotomy, whether preserving deltoid muscle, whether applying mesh patch and anchors had significant effects on the abduction angle of shoulder joint; the length of osteotomy, whether applying mesh patch and anchors had significant effects on the degree of upward displacement of prosthesis. The application of both mesh patch and anchors in prosthesis reconstruction achieved more stable result and better function of shoulder joint. To ensure the stability of shoulder joint and the firm wrapping of surrounding soft tissue are key factors affecting the postoperative function.

Proximal Humerus Tumors: Higher-than-Expected Risk of Revision With Constrained Reverse Shoulder Arthroplasty

BACKGROUND

The treatment of proximal humerus tumors with endoprostheses is associated with a high risk of implant-related surgical complications. Because of extensive soft-tissue resection and muscular detachment during surgery, instability is the most common serious complication. A reverse total shoulder arthroplasty with a highly constrained design is one option to mitigate instability, but few studies have reported the results of this prosthesis for proximal humerus tumor resections.

QUESTIONS/PURPOSES

(1) What are the short-term functional results of the constrained reverse total shoulder prosthesis in terms of Musculoskeletal Tumor Society (MSTS), DASH, and Constant-Murley scores and ROM values? (2) What is the frequency of revision, using a competing-risks estimator to assess implant survival, and what were the causes of the revisions that occurred? (3) What proportion of patients experienced dislocations at short-term follow-up?

METHODS

Between January 2014 and June 2017, we treated 55 patients with proximal humeral resections and reconstructions for malignant tumors. Of those, 33% (18) of patients were treated with the constrained, reverse total shoulder arthroplasty implant under study here. During that period, no other constrained reverse total shoulder implant was used; however, 13% (seven) of patients were treated with conventional (unconstrained) reverse total shoulder implants, 27% (15) had hemiarthroplasties, 15% (eight) of patients had biologic reconstructions with auto- or allografts and 13% (seven) underwent amputation. During the period in question, our general indications for use of the constrained device under study here were resection of the deltoid muscle/axillary nerve or the deltoid insertion on the humerus due to tumor invasion, or extensive rotator cuff and surrounding soft tissue resection that might result in shoulder instability. During this period, these indications were adhered to consistently. Four of 18 patients treated with the study implant died (three died with the implant intact) and none were lost to follow-up before 2 years, leaving 14 patients (seven women and seven men) for study at a median (range) follow-up of 35 months (25 to 65). Two authors evaluated the clinical and functional status of each patient with ROM (flexion, extension, internal and external rotation, abduction, and adduction) and MSTS, (range 0% to 100%), Constant-Murley (range 0% to 100%), and DASH (range 0 points to 100 points) scores. For the MSTS and Constant-Murley scores, higher percentage scores mean better functional outcome; and for the DASH score, a higher score means more severe disability. Radiographs were obtained at each visit and were used to look for signs of loosening, which we defined as progressive radiolucencies between visits, prosthetic component migration, and fragmentation/fracture of the cement. The Sirveaux classification was used to determine scapular notching. A competing risks analysis with 95% confidence intervals was performed to estimate the cumulative incidence of revision surgery, which we defined as any reoperation in which the implant was removed or changed for any reason, with patient mortality as a competing event.

RESULTS

At the most recent follow-up, the median (range) MSTS score was 78% (50 to 90), the DASH score was 20 (8 to 65), and the Constant-Murley score was 53% (26 to 83). The median ROM was 75° in forward flexion (40 to 160), 78° in abduction (30 to 150), 35° in internal rotation (10 to 80), and 33° in external rotation (0 to 55). Postoperatively, two of 14 patients underwent or were supposed to undergo revision surgery, and the cumulative incidence of revision surgery was 18% for both 30 and 48 months (95% CI 2 to 45). During the study period, no patients reported instability, and no dislocations occurred.

CONCLUSIONS

Our findings are concerning because the revision risk with this constrained reverse total shoulder implant was higher than has been reported by others for other proximal humerus prostheses. The highly constrained design that helps prevent instability might also transmit increased stresses to the humeral component-bone interface, therefore making it susceptible to loosening. We believe that any other implant with a similar degree of constraint will have the same problem, and changing the indications for patient selection may not solve this issue. These theories need to be tested biomechanically, but our desire is to warn surgeons that while trying to prevent instability, one might trade one complication (instability) for another: aseptic loosening.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Constrained or unconstrained shoulder replacement for musculoskeletal tumor resections?

BACKGROUND

Many options exist for reconstructing the shoulder after large bony resections of the proximal humerus. One of the more widely used is endoprosthetic replacement. Proximal migration of unconstrained hemiarthroplasty articulations may cause difficulties particularly in the setting of loss of the rotator cuff and/or deltoid musculature. To attempt to overcome these issues, a fixed-fulcrum constrained reverse shoulder replacement option may be considered.

METHODS

A retrospective review of prospectively collected data from the Queensland Bone and Soft Tissue Sarcoma Service was undertaken to compare the function, implant survivorship, and reoperation rate of constrained reverse and unconstrained hemiarthroplasty-type endoprostheses in patients with tumors.

RESULTS

We retrospectively reviewed data on 41 consecutive proximal or total humeral endoprosthetic replacements undertaken between January 2003 and July 2018. One patient was excluded as lost to follow-up prior to 24 months. There were 21 unconstrained implants and 19 constrained shoulder replacements (Stanmore Modular Endoprosthesis Tumour System with Bayley-Walker articulation). Proximal migration of the unconstrained hemiarthroplasty articulation occurred in 8 patients (38%), and dislocation or failure of the constrained mechanism occurred in 5 (26%). Reoperation for implant-related issues was required in 5 patients in the constrained group and none in the unconstrained group. Of the 18 patients alive at the time of review, 12 provided functional scores. The mean follow-up period for surviving patients was 4.2 years (standard deviation, 2.7 years), with a minimum of 2 years' follow-up. Functional scores were similar between the 2 groups.

CONCLUSION

Constrained reverse prostheses were associated with a higher reoperation rate in this series without any functional benefit compared with unconstrained hemiarthroplasty-type articulations. We favor the use of unconstrained hemiarthroplasty-type endoprostheses for reconstruction after resection of destructive lesions of the proximal humerus.

Long term outcomes of total humeral replacement for oncological reconstructions: A single institution experience

BACKGROUND

There is a paucity of data on long-term survivorship and outcomes for total humerus replacements (THR) with only two series reporting 10-year survival.

PATIENTS AND METHODS

A review of 769 consecutive, prospectively collected endoprosthetic reconstructions for oncological diagnoses at a single-center between 1980 and 2019 was performed. Patients with THRs were isolated and analyzed for outcomes, complications, and modes of failure.

RESULTS

Eighteen patients with 20 THR implants were identified. The median follow-up for surviving patients was 148 months (interquartile range [IQR] = 74-194) and 60 months (IQR = 17-155 months) for all patients. Two prostheses required revision for failure, both for symptomatic shoulder dislocation. There were three local recurrences. Revision-free survival at 5, 10, and 15 years was 100%, 86% and 86%, respectively. There were no cases of ulnar component failure, radial nerve palsy, or periprosthetic infection.

CONCLUSIONS

THR prosthesis survivorship is comparable to the previous series, with a longer follow-up than has previously been reported. Symptomatic shoulder instability was common (25%), and was the only cause of revision. Reverse total shoulder could be an important way to address this in the future. Local recurrence rates were high, as has been reported elsewhere for THR.

Endoprosthetic Reconstruction of the Upper Extremity in Oncologic Surgery

In 1943, Austin Moore successfully reconstructed a proximal femur using a Vitallium endoprosthesis. This marked the first successful alternative to amputation in oncologic surgery. However, it was not until the introduction of high-resolution axial imaging and improved chemotherapeutics that the feasibility of limb salvage began to improve. Today, limb salvage surgery can be used to treat most oncologic conditions of the extremities, the most popular reconstruction option being endoprostheses. Megaprostheses use has expanded to nononcologic indications with severe bone loss, including infections, revision arthroplasty, and severe periarticular trauma and its sequelae. The proximal humerus and scapula are challenging for reconstruction, given the complex anatomy of the brachial plexus, the accompanying vascular structures, and the dynamic stabilizers of the relatively nonstable glenohumeral joint. The midhumerus is difficult because of the close location of the radial nerve, whereas the distal humerus is challenging because of the proximity of the brachial artery and its bifurcation, radial, ulnar, and median nerves, and lack of soft-tissue coverage. Despite these challenges, this review demonstrates that many series show excellent mid- to long-term results for pain relief and function restoration after megaprosthetic reconstruction of the scapula and humerus after bone resections for oncologic and nononcologic reasons.

What Is the Survival and Function of Modular Reverse Total Shoulder Prostheses in Patients Undergoing Tumor Resections in Whom an Innervated Deltoid Muscle Can Be Preserved?

BACKGROUND

After proximal humerus resection for bone tumors, restoring anatomy and shoulder function remains demanding because muscles and bone are removed to obtain tumor-free surgical margins. Current modes of reconstruction such as anatomic modular prostheses, osteoarticular allografts, or allograft-prosthetic composites and arthrodeses are associated with relatively poor shoulder function related to loss of the deltoid and rotator cuff muscles. Newer prosthetic designs like the reverse total shoulder arthroplasty (RTSA) are felt to be useful in other reconstructions where rotator cuff function is compromised, so it seemed logical that it might help in tumor reconstructions as well in patients where the deltoid muscle and its innervation can be preserved.

QUESTIONS/PURPOSES

In patients with a tumor of the proximal humerus that can be resected with preservation of the deltoid muscle, (1) What complications are associated with tumor resection and reconstruction with a modular RTSA? (2) What are the functional results of modular RTSA in these patients?

METHODS

From January 2011 to January 2018, we treated 52 patients for bone tumors of the proximal humerus. Of these, three patients were treated with forequarter amputation, 14 were treated with standard modular proximal humerus implants, seven were treated with allograft-prosthetic composites (RTSA-APC), and 28 were treated with a modular RTSA. Generally, we used anatomic modular prosthetic reconstruction if during the tumor resection none of the abductor mechanism could be spared. Conversely, we preferred reconstruction with RTSA if an innervated deltoid muscle could be spared, but the rotator cuff and capsule could not, using RTSA-APC or modular RTSA if humeral osteotomy was distal or proximal to deltoid insertion, respectively. In this study, we retrospectively analyzed only patients treated with modular RTSA after proximal humerus resection. We excluded three patients treated with modular RTSA as revision procedures after mechanical failure of previous biological reconstructions and three patients treated after December 2016 to obtain an expected minimum follow-up of 2 years. There were nine men and 13 women, with a mean (range) age of 55 years (18 to 71). Reconstruction was performed in all patients using silver-coated modular RTSA protheses. Patients were clinically checked according to oncologic protocol. Complications and function were evaluated at final follow-up by the treating surgeon (PR) and shoulder surgeon (AC). Complications were evaluated according to Henderson classification. Functional results were assessed with the Musculoskeletal Tumor Society score (range 0 points to 30 points), Constant-Murley score (range 0 to 100), and American Shoulder and Elbow Surgeons score (range 0 to 100). The statistical analysis was performed using Kaplan-Meier curves.

RESULTS

Complications occurred in five of 22 patients; there was a shoulder dislocation (Type I) in four patients and aseptic loosening (Type II) in one. Function in these patients on the outcomes scales we used was generally satisfactory; the mean Musculoskeletal Tumor Society score was 29, the mean Constant score was 61, and the mean American Shoulder and Elbow Surgeons score was 81.

CONCLUSIONS

Although this was a small series of patients with heterogeneous diagnoses and resection types, and we were not able to directly compare the results of this procedure with those of other available reconstructions, we found patients treated with RTSA achieved reasonable shoulder function after resection and reconstruction of a proximal humerus tumor. It may not be valuable in all tumor resections, but in patients in whom the deltoid can be partly spared, this procedure appears to reasonably restore short-term shoulder function. However, future larger studies with longer follow-up are needed to confirm these findings.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Reverse shoulder endoprosthesis for pathologic lesions of the proximal humerus: a minimum 3-year follow-up

BACKGROUND

The Bayley Walker (Stanmore Implants, Elstree, UK) reversed polarity, linked shoulder replacement is designed to provide stable function in the treatment of a painful shoulder with poor soft tissue coverage. We reviewed the results of the prosthesis in destructive pathologic lesions of the proximal humerus at a United Kingdom tumor center.

METHODS

We identified 8 patients (2 men, 6 women) in our database. Clinical information and functional outcome scores were collected, including range of movement, Toronto Extremity Salvage Score, the Musculoskeletal Tumor Score. Radiographs from the last clinic follow-up were analyzed.

RESULTS

Of the 8 patients, 2 were revisions for aseptic loosening around proximal humeral endoprosthetic replacements. Indications for surgery included chondrosarcoma in 4, metastatic disease in 2, Ewing sarcoma in 1, and osteomyelitis in 1. Patients were a mean age at diagnosis of 49 years (range, 16-78 years). One patient died of metastatic disease during follow-up. Mean follow-up was 49 months (range, 36-90 months). At the latest follow-up, there was 100% survivorship using revision as the end point. There were no local recurrences. Three of 5 patients returned to their previous occupation. Neuropathic pain developed in 1 patient postoperatively, but no other postoperative complications were noted. Radiographs showed no progressive lucencies or scapula notching. Mean range of movement at final follow-up was abduction, 62°; forward flexion, 71°; and external and internal rotation, 50°.

CONCLUSION

The Bayley Walker prosthesis gives excellent medium-term survivorship and pain relief in patients with pathologic lesions of the proximal humerus requiring wide local excision.

What is the Optimal Reconstruction Option after the Resection of Proximal Humeral Tumors? A Systematic Review

Purpose:

The proximal humerus is a common location for both primary and metastatic bone tumors. There are numerous reconstruction options after surgical resection. There is no consensus on the ideal method of reconstruction.

Methods:

A systematic review was performed with a focus on the surgical reconstructive options for lesions involving the proximal humerus.

Results:

A total of 50 articles and 1227 patients were included for analysis. Reoperation rates were autograft arthrodesis (11%), megaprosthesis (10%), RSA (17%), hemiarthroplasty (26%), and osteoarticular allograft (34%). Mechanical failure rates, including prosthetic loosening, fracture, and dislocation, were highest in allograft-containing constructs (APC, osteoarticular allograft, arthrodesis) followed by arthroplasty (hemiarthroplasty, RSA, megaprosthesis) and lowest for autografts (vascularized fibula, autograft arthrodesis). Infections involving RSA (9%) were higher than hemiarthroplasty (0%) and megaprosthesis (4%).

Postoperative function as measured by MSTS score were similar amongst all prosthetic options, ranging from 66% to 74%, and claviculo pro humeri (CPH) was slightly better (83%). Patients were generally limited to active abduction of approximately 45° and no greater than 90°. With resection of the rotator cuff, deltoid muscle or axillary nerve, function and stability were compromised even further. If the rotator cuff was sacrificed but the deltoid and axillary nerve preserved, active forward flexion and abduction were superior with RSA.

Discussion:

Various reconstruction techniques for the proximal humerus lead to relatively similar functional results. Surgical choice should be tailored to anatomic defect and functional requirements.

Constrained fixed-fulcrum reverse shoulder arthroplasty improves functional outcome in epileptic patients with recurrent shoulder instability

AIM: To report the results of fixed-fulcrum fully constrained reverse shoulder arthroplasty for the treatment of recurrent shoulder instability in patients with epilepsy.

METHODS: A retrospective review was conducted at a single facility. Cases were identified using a computerized database and all clinic notes and operative reports were reviewed. All patients with epilepsy and recurrent shoulder instability were included for study. Between July 2003 and August 2011 five shoulders in five consecutive patients with epilepsy underwent fixed-fulcrum fully constrained reverse shoulder arthroplasty for recurrent anterior shoulder instability. The mean duration of epilepsy in the cohort was 21 years (range, 5-51) and all patients suffered from grand mal seizures.

RESULTS: Mean age at the time of surgery was 47 years (range, 32-64). The cohort consisted of four males and one female. Mean follow-up was 4.7 years (range, 4.3-5 years). There were no further episodes of instability, and no further stabilisation or revision procedures were performed. The mean Oxford shoulder instability score improved from 8 preoperatively (range, 5-15) to 30 postoperatively (range, 16-37) (P = 0.015) and the mean subjective shoulder value improved from 20 (range, 0-50) preoperatively to 60 (range, 50-70) postoperatively (P = 0.016). Mean active forward elevation improved from 71° preoperatively (range, 45°-130°) to 100° postoperatively (range, 80°-90°) and mean active external rotation improved from 15° preoperatively (range, 0°-30°) to 40° (20°-70°) postoperatively. No cases of scapular notching or loosening were noted.

CONCLUSION: Fixed-fulcrum fully constrained reverse shoulder arthroplasty should be considered for the treatment of recurrent shoulder instability in patients with epilepsy.

Optimal baseplate rotational alignment for locking-screw fixation in reverse total shoulder arthroplasty: a three-dimensional computer-aided design study

BACKGROUND

Baseplate loosening in reverse total shoulder arthroplasty (RTSA) remains a concern. Placing peripheral screws into the 3 pillars of the densest scapular bone is believed to optimize baseplate fixation. Using a 3-dimensional computer-aided design (3D CAD) program, we investigated the optimal rotational baseplate alignment to maximize peripheral locking-screw purchase.

METHODS

Seventy-three arthritic scapulae were reconstructed from computed tomography images and imported into a 3D CAD software program along with representations of an RTSA baseplate that uses 4 fixed-angle peripheral locking screws. The baseplate position was standardized, and the baseplate was rotated to maximize individual and combined peripheral locking-screw purchase in each of the 3 scapular pillars.

RESULTS

The mean ± standard error of the mean positions for optimal individual peripheral locking-screw placement (referenced in internal rotation) were 6° ± 2° for the coracoid pillar, 198° ± 2° for the inferior pillar, and 295° ± 3° for the scapular spine pillar. Of note, 78% (57 of 73) of the screws attempting to obtain purchase in the scapular spine pillar could not be placed without an in-out-in configuration. In contrast, 100% of coracoid and 99% of inferior pillar screws achieved full purchase. The position of combined maximal fixation was 11° ± 1°.

CONCLUSIONS

These results suggest that approximately 11° of internal rotation is the ideal baseplate position for maximal peripheral locking-screw fixation in RTSA. In addition, these results highlight the difficulty in obtaining optimal purchase in the scapular spine.

Synthetic mesh improves shoulder function after intraarticular resection and prosthetic replacement of proximal humerus

BACKGROUND

Shoulder function often is limited after tumor resection and endoprosthetic replacement of the proximal humerus. This is partly attributable to the inability to reliably reattach rotator cuff tendons to the prosthesis and achieve adequate shoulder capsule repair with a metallic prosthesis. An option to attain these goals is to use synthetic mesh for the reconstruction, although the value of this method has not been well documented in the literature.

QUESTIONS/PURPOSES

We asked whether patients who had shoulder reconstruction using synthetic mesh had (1) better shoulder function; (2) improved ROM compared with shoulder reconstructions without mesh; and (3) more stable joints compared with those in patients with similar resections who had reconstructions without synthetic mesh.

METHODS

During a 5-year period, we performed 41 intraarticular resections with endoprosthetic reconstructions for malignancies in the proximal humerus meeting specified criteria to generate similarity in the study groups. Twelve patients (29%) were lost to followup before 24 months, leaving 29 patients available for review at a mean of 45 months (range, 24-70 months). This retrospective study compared 14 patients with soft tissue reconstruction that included synthetic mesh with 15 patients with soft tissue reconstruction without the use of synthetic mesh. The choice was made during consultation between the patient and surgeon, after reviewing the perceived advantages and disadvantages of each approach. A tumor band (ligament advanced reinforcement system) was used as synthetic mesh and wrapped around the prosthesis of the proximal humerus for soft tissue reconstruction in the reconstruction-with-mesh group. Study endpoints included the Musculoskeletal Tumor Society (MSTS) function scores, American Shoulder and Elbow Surgeons (ASES) score, shoulder ROM, and proximal migration of the humeral prosthesis.

RESULTS

The mean MSTS score for patients without synthetic mesh reconstruction was 20 ± 3 points (66%), whereas for patients with synthetic mesh reconstruction, the mean score was 24 ± 2 points (79%; p = 0.001). Patients with synthetic mesh reconstruction had a higher mean total ASES score (85 ± 1.1 points versus 72 ± 1.7 points; p = 0.025), and better function for activities of daily living. They also had better ROM on mean active forward flexion (p = 0.020), abduction (p < 0.001), and external rotation (p < 0.001) than patients without synthetic mesh reconstruction. Proximal migration of the prosthesis was observed in five of 15 of patients in the group without synthetic mesh reconstruction and in none of those treated with synthetic mesh (p = 0.042).

CONCLUSIONS

Patients with intraarticular resection and endoprosthetic replacement of the proximal humerus with reconstruction that included synthetic mesh had better shoulder function and ROM, and more stable joints than patients who had reconstruction without synthetic mesh. This result supports prior observations by others and it remains to be shown whether use of the ligament advanced reconstruction system is superior to other types of mesh or other types of reconstructions. Further investigation is needed but our results indicate that using mesh should be considered for patients with tumor resection and endoprosthetic replacement of the proximal humerus.

A reverse shoulder arthroplasty with increased offset for the treatment of cuff-deficient shoulders with glenohumeral arthritis

Inherent disadvantages of reverse shoulder arthroplasty designs based on the Grammont concept have raised a renewed interest in less-medialised designs and techniques. The aim of this study was to evaluate the outcome of reverse shoulder arthroplasty (RSA) with the fully-constrained, less-medialised, Bayley–Walker prosthesis performed for the treatment of rotator-cuff-deficient shoulders with glenohumeral arthritis. A total of 97 arthroplasties in 92 patients (53 women and 44 men, mean age 67 years (standard deviation (sd) 10, (49 to 85)) were retrospectively reviewed at a mean follow-up of 50 months ((sd 25) (24 to 96)). The mean Oxford shoulder score and subjective shoulder value improved from 47 (sd 9) and 24 points (sd 18) respectively before surgery to 28 (sd 11) and 61 (sd 24) points after surgery (p <  0.001). The mean pain at rest decreased from 5.3 (sd 2.8) to 1.5 (sd 2.3) (p < 0.001). The mean active forward elevation and external rotation increased from 42°(sd 30) and 9° (sd 15) respectively pre-operatively to 78° (sd 39) and 24° (sd 17) post-operatively (p < 0.001). A total of 20 patients required further surgery for complications; 13 required revision of components. No patient developed scapular notching.

The Bayley–Walker prosthesis provides reliable pain relief and reasonable functional improvement for patients with symptomatic cuff-deficient shoulders. Compared with other designs of RSA, it offers a modest improvement in forward elevation, but restores external rotation to some extent and prevents scapular notching. A longer follow-up is required to assess the survival of the prosthesis and the clinical performance over time.

Cite this article: Bone Joint J 2014;96-B:936–42.

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.

Reverse shoulder replacement after resection of the proximal humerus for bone tumours

We investigated the functional outcome in patients who underwent reverse shoulder replacement (RSR) after removal of a tumour of the proximal humerus. A total of 16 patients (ten women and six men) underwent this procedure between 1998 and 2011 in our hospital. Five patients died and one was lost to follow-up. Ten patients were available for review at a mean follow-up of 46 months (12 to 136). Eight patients had a primary and two patients a secondary bone tumour. At final follow up the mean range of active movement was: abduction 78° (30° to 150°); flexion 98° (45° to 180°); external rotation 32° (10° to 60°); internal rotation 51° (10° to 80°). The mean Musculoskeletal Tumor Society score was 77% (60% to 90%) and the mean Toronto Extremity Salvage Score was 70% (30% to 91%). Two patients had a superficial infection and one had a deep infection and underwent a two-stage revision procedure. In two patients there was loosening of the RSR; one dislocated twice. All patients had some degree of atrophy or pseudo-atrophy of the deltoid muscle. Use of a RSR in patients with a tumour of the proximal humerus gives acceptable results.

Short- or long-stem prosthesis for intramedullary bypass of proximal humeral fractures with severe metaphyseal bone loss: evaluation of primary stability in a biomechanical model

BACKGROUND

Proximal humeral fractures with substantial metaphyseal comminution are challenging to treat. In the elderly with osteoporotic bone, arthroplasty sometimes remains the only valuable option; however, the minimally required length of stem fixation is not known. The aim of this study was to investigate the primary stability of cemented short- and long-stem prostheses with different intramedullary fracture bypass lengths.

MATERIALS AND METHODS

Osteoporotic composite bone models of the humerus (Synbone, Malans, Switzerland) with 3 different fracture levels (group A, 6 cm distal to surgical neck; group B, 7 cm distal to surgical neck; and group C, 8 cm distal to surgical neck) were prepared with a cemented standard short (S)- or long (L)-stem prosthesis and were tested for torque to failure. As a reference, we used models with intact bone (group R-O) and a short-stem prosthesis implanted at the surgical neck (group R-P). The radiographic bypass index (BI) was calculated before testing (fracture level to stem tip [in millimeters]/outer cortical diameter at fracture level [in millimeters]).

RESULTS

The resulting BIs of each group were as follows: 1.7 in group A-S, 3.4 in group A-L, 1.4 in group B-S, 3.2 in group B-L, 1.0 in group C-S, and 2.9 in group C-L. Compared with group R-O, the torques to failure of groups B-S and C-S were significantly lower, whereas only group C-S was significantly weaker than group R-P (P < .01). Comparing short- and long-stem bypasses of different fracture heights, we found that only group C-L showed a significantly higher resistance to torque (P < .01).

CONCLUSIONS

A short-stem bypass with a BI of 1.7 was sufficient for primary stability tested by torque to failure in this biomechanical setting. For smaller BIs, a long-stem prosthesis should be considered.

LEVEL OF EVIDENCE

Basic science study, biomechanics.

Proximal humeral reconstruction using nail cement spacer in primary and metastatic tumours of proximal humerus

Limb salvage surgery for malignant tumours of proximal humerus is an operative challenge, where the surgeon has to preserve elbow and hand functions and retain shoulder stability with as much function as possible. We treated 14 consecutive patients with primary malignant or isolated metastasis of proximal humerus with surgical resection and reconstruction by nail cement spacer. There were 8 females and 6 males, with a mean age of 28.92 years (range 16-51 years) and a mean follow-up of 30.14 months (range 12-52 months). The diagnosis was osteosarcoma in 8 patients, chondrosarcoma in 4 patients and metastasis from thyroid and breast carcinoma in 1 patient each. One of our patients had radial nerve neuropraxia, 1 developed inferior subluxation and 3 developed distant metastasis. Two patients died of disease and one developed local recurrence leading to forequarter amputation, leaving a total of 11 patients with functional extremities for assessment at the time of final follow-up which was done using the Musculoskeletal Tumour Society (MSTS) score. Though we were able to preserve the elbow, wrist and hand functions in all patients, the abductor mechanism, deltoid muscle and axillary nerve were not salvageable in any of cases. The mean MSTS score at the time of final follow-up was 19.09. Thus, proximal humeral reconstruction using nail cement spacer is a technical simple, cost-effective and reproducible procedure which makes it a reliable option in subset of patients where the functions around the shoulder cannot be preserved despite costlier prosthesis.

The results of total humeral replacement following excision for primary bone tumour

Rarely, the extent of a malignant bone tumour may necessitate resection of the complete humerus to achieve adequate oncological clearance. We present our experience with reconstruction in such cases using a total humeral endoprosthesis (THER) in 20 patients (12 male and eight female) with a mean age of 22 years (6 to 59). We assessed the complications, the oncological and functional outcomes and implant survival. Surgery was performed between June 2001 and October 2009. The diagnosis included osteosarcoma in nine, Ewing's sarcoma in eight and chondrosarcoma in three. One patient was lost to follow-up. The mean follow-up was 41 months (10 to 120) for all patients and 56 months (25 to 120) in survivors. There were five local recurrences (26.3%) and 11 patients were alive at time of last follow-up, with overall survival for all patients being 52% (95% confidence interval (CI) 23.8 to 74) at five years. The mean Musculoskeletal Tumor Society score for the survivors was 22 (73%; 16 to 23). The implant survival was 95% (95% CI 69.5 to 99.3) at five years. The use of a THER in the treatment of malignant tumours of bone is oncologically safe; it gives consistent and predictable results with low rates of complication.