RESUMEN
BACKGROUND: Osteoarthritis of the glenohumeral joint is often associated with posterior glenoid wear. The purpose of this study was to determine the clinical and radiographic outcomes of a posteriorly augmented glenoid in patients who have a Walch B glenoid deformity when treated with anatomic total shoulder arthroplasty (aTSA). METHODS: At total of 68 primary aTSA patients with osteoarthritis and a Walch B glenoid deformity were treated with an 8° posteriorly augmented glenoid. All patients were evaluated and underwent scoring preoperatively and at latest follow-up with 5 clinical outcome scoring metrics; active range of motion (ROM) was also measured. The mean follow-up period was 50 months, with a 2-year minimum follow-up period. RESULTS: All patients experienced significant improvements in pain and function following aTSA with a posteriorly augmented glenoid, and 90% of patients exceeded the minimal clinically important difference threshold for the clinical outcome metric scores and ROM measures. Two-thirds of patients exceeded the substantial clinical benefit threshold for the clinical outcome metrics and ROM. Preoperatively, the humeral head was posteriorly subluxated an average of 73% for each Walch B glenoid type, and at latest follow-up, all humeral heads were re-centered on the posteriorly augmented glenoid. Two patients with augmented glenoids who had Walch B2 glenoids underwent revision for aseptic glenoid loosening. DISCUSSION: Anatomic total shoulder arthroplasty patients with Walch B glenoids receiving an 8° posteriorly augmented wedge glenoid experienced excellent clinical and radiographic outcomes with a patient satisfaction rate greater than 97% and a low complication rate at a mean follow-up of 50 months. Humeral head centering was maintained for each type of Walch B glenoid.
Asunto(s)
Artroplastía de Reemplazo de Hombro , Osteoartritis/diagnóstico por imagen , Osteoartritis/cirugía , Adulto , Anciano , Femenino , Humanos , Cabeza Humeral/cirugía , Masculino , Persona de Mediana Edad , Diferencia Mínima Clínicamente Importante , Satisfacción del Paciente , Diseño de Prótesis , Rango del Movimiento Articular , Estudios Retrospectivos , Escápula/cirugía , Prótesis de HombroRESUMEN
BACKGROUND: This study reports the clinical and radiographic outcomes of a hybrid cage glenoid compared with an age-matched, sex-matched, and follow-up-matched cohort of cemented all-polyethylene peg glenoids in patients undergoing anatomic total shoulder arthroplasty with 2 years' minimum follow-up. MATERIALS AND METHODS: We reviewed 632 primary anatomic total shoulder arthroplasty patients from an international multi-institutional database; 316 patients received hybrid cage glenoids and were matched for age, sex, and follow-up with 316 patients with cemented all-polyethylene peg glenoids. Each cohort received the same humeral component. Scoring was performed in all patients preoperatively and at latest follow-up using 5 outcome scoring metrics and 4 active range-of-motion measurements. A Student 2-tailed unpaired t test identified differences in outcomes; P < .05 denoted a significant difference. RESULTS: Cage glenoid patients had significantly lower rates of radiolucent glenoid lines (9.0% vs. 37.6%, P < .0001) and radiolucent humeral lines (3.0% vs. 9.1%, P = .0088) than all-polyethylene peg glenoid patients. In the cage glenoid cohort, 4 cases of aseptic glenoid loosening (1.3%) and 4 cases of articular surface dissociation (1.3%) occurred. In the all-polyethylene peg cohort, 12 cases of aseptic loosening (3.8%) occurred. Cage glenoid patients had a significantly lower revision rate than all-polyethylene peg glenoid patients (2.5% vs. 6.9%, P = .0088). CONCLUSION: At 50 months' mean follow-up, cage glenoids demonstrated equally good clinical outcomes to all-polyethylene peg glenoids. Cage glenoids had significantly fewer radiolucent lines around both the glenoid and humeral components and a lower revision rate. Longer-term follow-up is required to confirm these promising short-term results.
Asunto(s)
Artroplastía de Reemplazo de Hombro/instrumentación , Cavidad Glenoidea/cirugía , Articulación del Hombro/diagnóstico por imagen , Articulación del Hombro/fisiopatología , Prótesis de Hombro , Adulto , Anciano , Anciano de 80 o más Años , Bases de Datos Factuales , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Polietileno , Diseño de Prótesis/efectos adversos , Falla de Prótesis/etiología , Reoperación , Estudios Retrospectivos , Articulación del Hombro/cirugía , Prótesis de Hombro/efectos adversos , Factores de Tiempo , Resultado del TratamientoRESUMEN
INTRODUCTION: ASTM F2028-14 was adopted to recom mend a cyclic eccentric glenoid edge loading test that simulates the rocking horse loading mechanism beleived to cause aTSA glenoid loosening. While this method accurately simulates that failure mechanism, the recommended 750 N load may not be sufficient to simulate worst-case loading magnitudes, and the recommended 100,000 cycles may not be sufficient to simulate device fatigue-related failure modes. Finally, if greater loading magnitude or a larger number of cycles is performed, the recommended substrate density may not be sufficiently strong to support the elevated loads and cycles. To this end, a new test method is proposed to supplement ASTM F2028-14. METHODS: A series of cyclic tests were performed to evaluate the long-term fixation strength of two different hybrid glenoid designs in both low (15 pcf) and high (30 pcf) density polyurethane blocks at elevated loads relative to ASTM F2028-14. To simulate a worst case clinical condition in which the humeral head is superiorly migrated, a cyclic load was applied to the superior glenoid rim to induce a maximum torque on the fixation pegs for three different cyclic loading tests: 1. 1,250 N load for 0.75 M cycles in a 15 pcf block, 2. 1,250 N load for 1.5 M cycles in a 30 pcf block, and 3. 2,000 N load for 0.65 M cycles in a 30 pcf block. RESULTS: All devices completed cyclic loading without failure, fracture, or loss of fixation regardless of glenoid design, polyurethane density, loading magnitude, or cycle length. No significant difference in post-cyclic displacement was noted between designs in any of the three tests. Post-cyclic radiographs demonstrated that each device maintained fixa - tion with the metal pegs within the bone-substitute blocks with no fatigue related failures. DISCUSSION: These results demonstrate that both cemented hybrid glenoids maintained fixation when tested according to each cyclic loading scenario, with no difference in post-cyclic displacement observed between designs. The lack of fatigue-related failures in these elevated load and high cycle test scenarios are promising, as are the relatively low displacements given the extreme nature of each test. This cyclic loading method is intended to supplement the ASTM F2028-14 standard that adequately simulates the rocking horse loading mechanism but may not adequately simulate the fatigue-related failure modes.
Asunto(s)
Artroplastia de Reemplazo/instrumentación , Cavidad Glenoidea/cirugía , Prótesis Articulares , Falla de Prótesis , Articulación del Hombro/cirugía , Artroplastia de Reemplazo/efectos adversos , Fenómenos Biomecánicos , Sustitutos de Huesos , Análisis de Falla de Equipo , Cavidad Glenoidea/fisiopatología , Humanos , Ensayo de Materiales , Poliuretanos , Diseño de Prótesis , Articulación del Hombro/fisiopatología , Estrés MecánicoRESUMEN
INTRODUCTION: Osteoarthritis of the shoulder often results in significant posterior glenoid wear. The options for treating this have been eccentric glenoid reaming and occasionally bone grafting. More recently reverse total shoulder arthroplasty (rTSA) with or without bone grafting and posterior augmented glenoids (PAGs) has been introduced. The PAG restores the native joint line while reaming a minimal amount of glenoid bone. The purpose of this study is to compare osteoarthritic shoulders with significant posterior glenoid wear treated with anatomic total shoulder arthroplasty (aTSA) using a PAG to shoulders without glenoid wear treated with aTSA using a standard all poly pegged glenoid. METHODS: The patients' data in this study were retrospectively queried from prospectively acquired data in a multi-institutional IRB approved database. The study population consisted of 24 patients with osteoarthritis and posterior glenoid wear who were treated with aTSA using a PAG with a minimum of two-year follow-up. This population was age, sex, and follow-up matched to patients treated with an all poly non-augmented pegged glenoid (NAG) for osteoarthritis. Seven females and 17 males with an average age of 65.8 ± 11.5 years received a posterior augmented glenoid. The control group consisted of 7 females and 17 males with an average age of 66.4 ± 9.1 years who underwent aTSA for osteoarthritis using an all poly standard glenoid. These age, gender, and follow-up matched patients were evaluated and scored preoperatively and at latest follow-up using the SST, UCLA, ASES, Constant, and SPADI scoring metrics; active abduction, elevation, and external rotation were also measured. A Grashey and axillary lateral radiograph was evaluated at two-year follow-up. The Shoulder Arthroplasty Subluxation Index was used to determine the degree of humeral component subluxation on the glenoid component. A Student's two-tailed, unpaired t-test was used to identify differences in preoperative and postoperative results, where p < 0.05 denoted a significant difference. RESULTS: All patients demonstrated significant improvements in pain and function with the primary aTSA. Sixty per-cent of PAG shoulders had a radiolucent line with an average radiographic line score of 1.10, and 33.3% of NAG had a radiolucent line with an average radiographic line score of 0.438. One glenoid in the PAG group is radiographically but not clinically loose. In the PAG group, the Grashey view showed that 18/20 humeral heads were centered with the two remaining joints demonstrating superior subluxation. On the axillary lateral in the PAG group, 17/20 humeral heads were centered, and three were anteriorly subluxated; none were posteriorly subluxated. There were no differences in any of the measured postoperative clinical outcomes or any difference in improvement between the two groups. DISCUSSION: At a minimum of two-year follow-up, there were no statistical clinical differences between the PAG and NAG groups despite the PAG group being disadvantaged with posterior worn glenoids. There were no revisions in either group. No humeral heads resubluxated posteriorly. The PAG group had a higher incidence of lucent lines. Based on this short-term follow-up, a posterior augmented glenoid is a viable option for the posterior worn osteoarthritic glenoid.
Asunto(s)
Artroplastia de Reemplazo/instrumentación , Cavidad Glenoidea/cirugía , Prótesis Articulares , Osteoartritis/cirugía , Polietileno , Articulación del Hombro/cirugía , Anciano , Artroplastia de Reemplazo/efectos adversos , Fenómenos Biomecánicos , Bases de Datos Factuales , Femenino , Cavidad Glenoidea/diagnóstico por imagen , Cavidad Glenoidea/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Osteoartritis/diagnóstico , Osteoartritis/fisiopatología , Dimensión del Dolor , Diseño de Prótesis , Falla de Prótesis , Recuperación de la Función , Estudios Retrospectivos , Articulación del Hombro/diagnóstico por imagen , Articulación del Hombro/fisiopatología , Factores de Tiempo , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
INTRODUCTION: The aim of this study was to evaluate the preliminary outcomes of a hybrid cage glenoid design in comparison to pegged all-polyethylene glenoid components in anatomic total shoulder arthroplasty (aTSA). MATERIALS AND METHODS: Ninety-two patients undergoing primary anatomic total shoulder arthroplasty with minimum two-year follow-up were reviewed. Forty-six patients had an ultra-high molecular weight polyethylene (UHMWPE) cemented pegged glenoid component, and 46 had a hybrid cage glenoid component. Patient data was retrospectively reviewed from prospectively acquired data in a multi-institutional IRB approved database. These age, gender, and follow-up matched patients were evaluated and scored preoperatively and a latest follow-up using the SST, UCLA, ASES, Constant, and SPADI scoring metrics. Additional measures included active abduction, elevation, and external rotation. Radiolucent line assessment of the glenoid was performed by use of a Grashey and axillary radiograph at latest follow-up. A Student's two tailed, unpaired t-test was used to identify differences in preoperative and postoperative results, where p < 0.05 denoted a significant difference. RESULTS: All patients demonstrated significant improvements in pain and function following treatment with the primary aTSA. The database contained three complications for the aTSA patients with a cage glenoid, and three complications for patients with a UHMWPE pegged glenoid. Radiographic data was available for 37 of 46 cage glenoid patients and 29 of 46 UHMWPE pegged glenoid patients. Five of 37 cage glenoid patients had a radiolucent line (13.5%) with an average radiographic line score of 0.22. Eight of 29 UHMWPE peg glenoid patients had a radiolucent line (27.6%) with an average radiographic line score of 0.57. Cage aTSA patients were associated with significantly less blood loss than aTSA UHMWPE pegged glenoid patients (avg. blood loss = 242 vs. 337; p = 0.022). CONCLUSION: At minimum two-year follow-up, hybrid cage aTSA components show equal clinical outcomes to UHMWPE pegged glenoids. However, the hybrid cage components had significantly fewer radiolucent lines and less intra-operative blood loss. Additional and longer-term clinical and radiographic follow-up is necessary to confirm these promising early results.
Asunto(s)
Artroplastia de Reemplazo/instrumentación , Cavidad Glenoidea/cirugía , Prótesis Articulares , Diseño de Prótesis , Articulación del Hombro/cirugía , Anciano , Artroplastia de Reemplazo/efectos adversos , Fenómenos Biomecánicos , Bases de Datos Factuales , Femenino , Cavidad Glenoidea/diagnóstico por imagen , Cavidad Glenoidea/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Polietileno , Complicaciones Posoperatorias/etiología , Radiografía , Estudios Retrospectivos , Articulación del Hombro/diagnóstico por imagen , Articulación del Hombro/fisiopatología , Factores de Tiempo , Resultado del TratamientoRESUMEN
INTRODUCTION: This study quantified bone removed to correct three different sizes of posterior glenoid defects and also quantified the change in rotator cuff muscle length resulting from correction of each defect using three different glenoid designs. METHODS: A 3-D computer model quantified the cortical and cancellous bone removed when correcting three sizes of posterior glenoid defects and simulated internal/external rotation to quantify changes in rotator cuff muscle length when correcting glenoid retroversion in three sizes of posterior glenoid defects using three different glenoid prostheses: 1. eccentric reaming using a non-augmented glenoid (Equinoxe standard pegged), 2. 8°, 12°, and 16° Equinoxe posterior augment glenoid (wedge), and 3. 3 mm, 5 mm, and 7 mm Global Step-Tech posterior augment glenoid (step). RESULTS: For small defects, the 8° wedge and 3 mm step posterior augment glenoids conserves 50% (1.295 cm 3 ) and 23% (1.704 cm 3 ) more bone than eccentric reaming (2.147 cm 3 ), respectively. For medium defects, the 12° wedge and 5 mm step glenoids conserves 69% more (1.295 cm 3 ) and 2% less (2.720 cm 3 ) bone than eccentric reaming (2.655 cm 3 ), respectively. For large defects, the 16° wedge and 7 mm step glenoids conserve 48% more (1.852 cm 3 ) and 36% less (4.343 cm 3 ) bone than eccentric reaming (3.736 cm 3 ), respectively. For each size defect, muscle shortening was observed for both eccentric reaming and each augmented glenoid design. Eccentric reaming medialized the humerus and resulted in additional muscle shortening (wedge: 2.0%, 2.9%, and 3.6%; step: 1.2%, 1.7%, and 1.7%) in each size defect, respectively. DISCUSSION AND CONCLUSIONS: Both step and wedge augmented glenoid designs conserved more anterior glenoid bone and were associated with less muscle shortening than correction with eccentric reaming. However, wedge posterior augment glenoids medialized the humerus less and were observed to be more bone conserving than step posterior augment glenoids, particular in large glenoid defects.
Asunto(s)
Artroplastia de Reemplazo/métodos , Cavidad Glenoidea/patología , Húmero/cirugía , Manguito de los Rotadores/cirugía , Articulación del Hombro/cirugía , Artroplastia de Reemplazo/efectos adversos , Fenómenos Biomecánicos , Simulación por Computador , Cavidad Glenoidea/cirugía , Humanos , Húmero/fisiopatología , Manguito de los Rotadores/fisiología , Articulación del Hombro/fisiopatologíaRESUMEN
Shoulder arthroplasty represents one of the fastest growing orthopaedic procedures in the USA. In comparison to hemiarthroplasty, total shoulder arthroplasty has higher patient satisfaction and lower revision rates. Aseptic glenoid loosening remains a concern for longevity of total shoulder arthroplasties. Cement fixation on the glenoid side represents the primary and only mode of fixation in the majority of implants in the USA. Metal backed glenoid designs have demonstrated higher failure rates, primarily due to thinning of the polyethylene bearing surface. We reviewed our early experience and results with a novel glenoid design. Long-term fixation in this design is provided by a central metallic bone ingrowth cage, without the need for metal backing.
Asunto(s)
Artroplastia de Reemplazo/métodos , Cementos para Huesos/uso terapéutico , Cavidad Glenoidea/cirugía , Prótesis Articulares , Diseño de Prótesis/métodos , Articulación del Hombro/cirugía , Humanos , Resultado del TratamientoRESUMEN
Treatment of rotator cuff deficient shoulders continues to evolve. Reverse total shoulder arthroplasty has proven effective for restoring forward elevation and abduction in patients who suffer from pseudoparalysis secondary to rotator cuff insufficiency. Unfortunately, reverse total shoulder arthroplasty is less effective at restoring lost external rotation function in patients with deficient posterior rotator cuff tissue. Therefore, functional results of reverse arthroplasty in patients who demonstrate preoperative lag signs is inferior to patients with functioning posterior rotator cuff musculature. Combined latissimus dorsi and teres major tendon transfers have been shown to be effective treatment for patients with isolated loss of external rotation. These transfers have also been shown to improve functional results in patients who undergo reverse arthroplasty and have combined loss of forward elevation and external rotation preoperatively. Previously published studies have evaluated the combined reverse arthroplasty and tendon transfer procedure only in patients with first generation (medial center of rotation) implants. We reviewed our experience with the combined procedure utilizing a third generation (medial center of rotation glenoid and lateral center of rotation humerus) device.
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Artroplastia de Reemplazo/métodos , Músculo Esquelético/cirugía , Manguito de los Rotadores/cirugía , Articulación del Hombro/cirugía , Músculos Superficiales de la Espalda/cirugía , Transferencia Tendinosa/métodos , Tendones/cirugía , Artroplastia de Reemplazo/efectos adversos , Humanos , Músculo Esquelético/fisiopatología , Rango del Movimiento Articular , Manguito de los Rotadores/fisiopatología , Articulación del Hombro/fisiopatología , Transferencia Tendinosa/efectos adversos , Resultado del TratamientoRESUMEN
PURPOSE: The purpose of this study is to validate a reverse shoulder computer impingement model and quantify the impact of implant position on scapular impingement by comparing it to that of a radiographic analysis of 256 patients who received the same prosthesis and were followed postoperatively for an average of 22.2 months. METHODS: A geometric computer analysis quantified anterior and posterior scapular impingement as the humerus was internally and externally rotated at varying levels of abduction and adduction relative to a fixed scapula at defined glenoid implant positions. These impingement results were compared to radiographic study of 256 patients who were analyzed for notching, glenoid baseplate position, and glenosphere overhang. RESULTS: The computer model predicted no impingement at 0° humeral abduction in the scapular plane for the 38 mm, 42 mm, and 46 mm devices when the glenoid baseplate cage peg is positioned 18.6 mm, 20.4 mm, and 22.7 mm from the inferior glenoid rim (of the reamed glenoid) or when glenosphere overhang of 4.6 mm, 4.7 mm, and 4.5 mm was obtained with each size glenosphere, respectively. When compared to the radiographic analysis, the computer model correctly predicted impingement based upon glenoid base- plate position in 18 of 26 patients with scapular notching and based upon glenosphere overhang in 15 of 26 patients with scapular notching. CONCLUSIONS: Reverse shoulder implant positioning plays an important role in scapular notching. The results of this study demonstrate that the computer impingement model can effectively predict impingement based upon implant positioning in a majority of patients who developed scapular notching clinically. This computer analysis provides guidance to surgeons on implant positions that reduce scapular notching, a well-documented complication of reverse shoulder arthroplasty.