RESUMEN
BACKGROUND: This study reports the outcome of resurfacing hemiarthroplasty (RHA) in a cohort of patients with juvenile idiopathic arthritis (JIA) affecting the shoulder joint METHODS: Fourteen uncemented RHA procedures were performed for 11 consecutive patients who required surgery because of JIA. Mean age at surgery was 36.4 years. Mean clinical follow-up was 10.4 years (range, 5.8-13.9 years). A significant humeral head defect (up to 40% surface area) was found in 5 shoulders and filled with autograft from the distal clavicle or femoral head allograft. RESULTS: At latest follow-up, no patient required revision. There was excellent relief from pain. The mean Oxford Shoulder Score and Constant-Murley Score improved significantly. No shoulder had a poor outcome, and 6 had a very good or excellent outcome. Worse outcome was associated with an intraoperative finding of significant humeral head erosion. Two shoulders required early arthroscopic subacromial decompression, but there were no other reoperations. There were no instances of radiographic implant loosening or proximal migration. Painless glenoid erosion was seen in 5 shoulders but was not associated with worse outcome. CONCLUSIONS: The midterm results of RHA for JIA are at least comparable to those for stemmed hemiarthroplasty, with the added benefit of bone conservation.
Asunto(s)
Artritis Juvenil/cirugía , Hemiartroplastia , Articulación del Hombro/cirugía , Adulto , Aloinjertos , Clavícula/trasplante , Femenino , Cabeza Femoral/trasplante , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Evaluación del Resultado de la Atención al Paciente , Rango del Movimiento Articular , Estudios Retrospectivos , Articulación del Hombro/diagnóstico por imagen , Adulto JovenRESUMEN
PURPOSE: The aim of this multicentre cohort study was to evaluate the midterm outcomes and survival after cementless stemless resurfacing arthroplasty (CSRA) in a series of 33 shoulders in 27 patients with primary osteoarthritis. METHODS: Clinical outcome assessment included: Constant-Murley score (CMS); Simple Shoulder Test (SST); Disability of Arm, Shoulder, Hand (DASH); EuroQol-5D (EQ-5D) utility scores; Numerous Rating Scale (NRS) for pain. Radiographs were assessed by two independent observers for oversizing, radiolucency, glenohumeral subluxation, glenoid erosion and subsidence. Correlations between the clinical and radiological outcomes were calculated. Complications were registered, and revision and survival rates were calculated. RESULTS: Mean age at time of surgery and mean follow-up time were, respectively, 67.7 (range 50.2-85.1) and 7.2 years (range 5.7-9.3 years). Means (SD) for CMS, age- and gender-adjusted CMS, SST, DASH and EQ-5D utility scores were: 56.4 (20.2), 76.5 (25.0), 54.0 (29.8), 37.6 (23.3) and 0.8 (0.1), respectively. NRS for pain was 2.0 and 3.8, respectively, in rest and during activities. Radiographic assessment of the CSRAs showed oversizing in 54.5%; radiolucency in 18.2%; superior glenohumeral subluxation in 33.3%; glenoid erosion in 45.5%; and subsidence in 3.0%. Perioperative complications did not occur. Revision surgery was performed in one patient (3.0%). CONCLUSION: For primary osteoarthritis, the CSRA showed good clinical but poor radiological outcomes at midterm follow-up.
Asunto(s)
Hemiartroplastia/métodos , Osteoartritis/cirugía , Articulación del Hombro/cirugía , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Hemiartroplastia/efectos adversos , Humanos , Luxaciones Articulares/etiología , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Falla de Prótesis , Reoperación , Estudios Retrospectivos , Articulación del Hombro/diagnóstico por imagen , Articulación del Hombro/fisiopatologíaRESUMEN
BACKGROUND: The deltopectoral approach for total shoulder arthroplasty can result in subscapularis dysfunction. In addition, glenoid wear is more prevalent posteriorly, a region difficult to access with this approach. We propose a posterior approach for access in total shoulder arthroplasty that uses the internervous interval between the infraspinatus and teres minor. This study compares this internervous posterior approach with other rotator cuff-sparing techniques, namely, the subscapularis-splitting and rotator interval approaches. METHODS: The 3 approaches were performed on 12 fresh frozen cadavers. The degree of circumferential access to the glenohumeral joint, the force exerted on the rotator cuff, the proximity of neurovascular structures, and the depth of the incisions were measured, and digital photographs of the approaches in different arm positions were analyzed. RESULTS: The posterior approach permits direct linear access to 60% of the humeral and 59% of the glenoid joint circumference compared with 39% and 42% for the subscapularis-splitting approach and 37% and 28% for the rotator interval approach. The mean force of retraction on the rotator cuff was 2.76 (standard deviation [SD], 1.10) N with the posterior approach, 2.72 (SD, 1.22) N with the rotator interval, and 4.75 (SD, 2.56) N with the subscapularis-splitting approach. From the digital photographs and depth measurements, the estimated volumetric access available for instrumentation during surgery was comparable for the 3 approaches. CONCLUSION: The internervous posterior approach provides greater access to the shoulder joint while minimizing damage to the rotator cuff.
Asunto(s)
Artroplastía de Reemplazo de Hombro/métodos , Articulación del Hombro/cirugía , Anciano , Anciano de 80 o más Años , Cadáver , Estudios de Factibilidad , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Fotograbar , Manguito de los RotadoresRESUMEN
BACKGROUND: There are multiple techniques to approach the glenohumeral joint. Our purpose was to quantify the average area of the glenohumeral joint exposed with 3 subscapularis approaches and determine the least invasive approach for placement of shoulder resurfacing and total shoulder arthroplasty instruments. METHODS: Ten forequarter cadaveric specimens were used. Subscapularis approaches were performed sequentially from split, partial tenotomy, and full tenotomy through the deltopectoral approach. Glenohumeral joint digital photographs were analyzed in Image J software (National Institutes of Health, Bethesda, MD, USA). Shoulder resurfacing and total shoulder arthroplasty instruments were placed on the humeral head, and anatomic landmarks were identified. RESULTS: The average area of humeral head visible, from the least to the most invasive approach, was 3.2, 8.1, and 11.0 cm2, respectively. The average area of humeral head visible differed significantly according to the approach. Humeral head area increased 157% when the subscapularis split approach was compared with the partial tenotomy approach and 35% when the partial approach was compared with the full tenotomy approach. The average area of glenoid exposed from least to most invasive approach was 2.0, 2.3, and 2.5 cm2, respectively. No significant difference was found between the average area of the glenoid and the type of approach. Posterior structures were difficult to visualize for the subscapularis split approach. Partial tenotomy of the subscapularis allowed placement of resurfacing in 70% of the specimens and total arthroplasty instruments in 90%. CONCLUSIONS: The subscapularis splitting approach allows adequate exposure for glenoid-based procedures, and the subscapularis approaches presented expose the glenohumeral joint in a step-wise manner. LEVEL OF EVIDENCE: Anatomy study, cadaver dissection.
Asunto(s)
Artroplastia de Reemplazo/métodos , Articulación del Hombro/cirugía , Adulto , Anciano , Artroplastia de Reemplazo/instrumentación , Cadáver , Femenino , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Mínimamente Invasivos , Músculo Esquelético/cirugía , Hombro/cirugía , Estados UnidosRESUMEN
Shoulder resurfacing is a versatile, bone-conserving procedure to treat arthritis, avascular necrosis, and rotator cuff arthropathy. Shoulder resurfacing is of interest to young patients who are concerned about implant survivorship and those in need of a high level of physical activity. Using a ceramic surface reduces wear and metal sensitivity to clinically unimportant levels. Between 1989 and 2018, 586 patients received cementless, ceramic-coated shoulder resurfacing implants for arthritis, avascular necrosis, or rotator cuff arthropathy. They were followed for a mean of 11 years and were assessed using the Simple Shoulder Test (SST) and Patient Acceptable Symptom State (PASS). CT scans were used in 51 hemiarthroplasty patients to assess the glenoid cartilage wear. Seventy-five patients had a stemmed or stemless implant in the contralateral extremity. A total of 94% of patients had excellent or good clinical results and 92% achieved PASS. 6% of patients required a revision. A total of 86% of patients preferred their shoulder resurfacing prosthesis over a stemmed or stemless shoulder replacement. The glenoid cartilage wear at a mean of 10 years was 0.6 mm by a CT scan. There were no instances of implant sensitivity. Only one implant was removed due to a deep infection. Shoulder resurfacing is an exacting procedure. It is clinically successful, with excellent long-term survivorship in young and active patients. The ceramic surface has no metal sensitivity, very low wear, and, therefore, it is successful as a hemiarthroplasty.
RESUMEN
Historically, the shoulder arthroplasty humeral component has been designed for the management of infections, tumours and fractures. In all these cases the stem was needed as a scaffold. Original humeral components were not developed for use in shoulder arthritis, so these designs and derivates had a long stem. The newest humeral implants innovations consist in shortening of the implant, or even removing the whole stem, to rely on stemless fixation at the level of the metaphysis. This implies the advantages of preserved bone stock, less stress shielding, eliminating the diaphyseal stress riser, easier implant removal at revision, and humeral component placement independent from the humeral diaphyseal axis. Nowadays, surgeons try to balance the need for a stable fixation of the humeral component with the potential need for revision surgery. Complications of revision shoulder arthroplasty are related to the need for removing a well-fixed humeral stem, the length of the procedure, and the need to treat severe bone loss.
RESUMEN
Shoulder replacement is indicated in the treatment of pain due to osteoarthritis. Few studies have objectively assessed range of motion (RoM) gains at different post-operative time points. This is a prospective 3D motion analysis study to objectively quantify RoM changes at multiple time points following shoulder resurfacing arthroplasty (SRA) for primary gleno-humeral osteoarthritis, comparing it with clinically measured RoM. Clinical assessment, Visual Analog Scale (VAS) pain score, Constant-Morley (CS) and Oxford Shoulder Score (OSS) were recorded. Motion analysis was performed for RoM and three activities of daily living tasks (ADL), pre-operatively and post-operatively at 4 and 12 months. Nineteen shoulders in fifteen patients were included. The mean age was 72 years (range 52-84). There were significant improvements in external and internal rotation, ability to place the hand behind the head and reach the fifth lumbar vertebra, at 4 months on clinical examination and kinematic analysis with no further improvements at 12 months. There was significant improvement in abduction at 4 months with further improvement at 12 months, which was significantly more than noted on clinical assessment. In contrast, kinematic analysis showed a reduction in flexion between 4 and 12 months, while clinically there appeared to be an improvement between these time periods. This is the first study to prospectively utilise objective kinematic 3-D motion analysis in addition to clinical measurements and outcome scores, to investigate the outcome of resurfacing arthroplasty at multiple time points after surgery, providing an understanding into the trends of change in these parameters.
Asunto(s)
Artroplastía de Reemplazo de Hombro , Hemiartroplastia , Articulación del Hombro , Actividades Cotidianas , Anciano , Anciano de 80 o más Años , Fenómenos Biomecánicos , Humanos , Persona de Mediana Edad , Estudios Prospectivos , Rango del Movimiento Articular , Hombro , Articulación del Hombro/cirugía , Resultado del TratamientoRESUMEN
BACKGROUND: Severe glenohumeral arthritis in the young/active patient remains challenging. Historically, glenohumeral arthrodesis was recommended with limited return of function. Total shoulder arthroplasty has shown increasing survivorship at 15 years; however it is still not ideal for young patients. Biologic resurfacing of the glenoid with humeral head replacement has shown promising results. METHODS: The PubMed and Embase databases were queried for studies evaluating outcomes of glenoid biologic resurfacing with autograft or allograft. Two independent reviewers performed a systematic review according to the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. RESULTS: Eleven studies (268 shoulders, 264 patients) were included. Minimum follow-up was 24 months in all but one study; patient age ranged from 14 to 75 years. Glenoid grafts used included 44.3% lateral meniscus allografts, 25.4% human acellular dermal matrix, 14.2% Achilles tendon allografts, 11.6% shoulder joint capsules, and 4.5% fascia lata autografts. Studies reported significantly improved American Shoulder and Elbow Surgeons, Visual Analog Scale, and Simple Shoulder Test scores postoperatively; 43.3% were failures (Neer's evaluation of unsatisfactory or requiring revision). Infection occurred in 12/235. CONCLUSIONS: Biologic resurfacing of the glenoid with a metallic humeral component can provide a significant improvement in pain, motion, and standardized outcomes scores in the well-indicated situation. Appropriate counseling is required with an appreciated complication rate of over 36% and a revision rate of 34%.
RESUMEN
PURPOSE: The aim of this study was to assess the reasons of failure of shoulder surface replacement hemiarthroplasty (SRH) and to evaluate the outcome of revision surgery. METHOD: The study group included 25 patients (26 shoulders) with failed SRHs. The mean time to revision surgery was 3.6 years. Their functional outcome was evaluated using adjusted Constant-Murley score at mean follow-up of 5.2 years (range 2-16 years). RESULT: Most common cause of failure was glenoid erosion (42%) and progressive failure of rotator cuff (31%). Median adjusted Constant-Murley score at mean follow-up of 5.2 years was 51.6. Median adjusted Constant-Murley score in patients who had primary diagnosis of osteoarthritis and had revision performed to anatomic TSA (14 shoulders) was 85 (range 40-100) at mean follow-up of 5 years compared to 36.3 (range 20-66.3) in the remaining patients at 5.4 years, p = 0.00008. CONCLUSION: Revision surgery for failed SRH can be technically challenging with variable results. Most common mode of failure was glenoid erosion. Functional outcomes are better in those with revision performed to anatomic TSA.
Asunto(s)
Artroplastía de Reemplazo de Hombro , Osteoartritis/cirugía , Reoperación/métodos , Anciano , Anciano de 80 o más Años , Artritis Reumatoide/cirugía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Infecciones Relacionadas con Prótesis/diagnóstico , Estudios Retrospectivos , Manguito de los Rotadores/diagnóstico por imagen , Escápula/diagnóstico por imagen , Dolor de Hombro/diagnóstico , Tiempo de Tratamiento , Insuficiencia del Tratamiento , Resultado del TratamientoRESUMEN
INTRODUCTION: Despite the good outcomes with shoulder resurfacing procedures reported by some authors, our team has documented several failures caused by glenoid erosion and rotator cuff rupture, likely due to implant overstuffing. The aim of this study was to evaluate the clinical and radiological outcomes of reverse shoulder arthroplasty (RSA) performed after failed humeral head resurfacing (HHR). MATERIAL AND METHODS: This was a retrospective, single-center study of 17 patients who underwent RSA after failed HHR between January 2011 and February 2016. The mean patient age was 69.4 years and the mean time between HHR and surgical revision was 41 months (14.7-73.5±18.8). Preoperative ultrasonography and CT were used to evaluate the condition of the rotator cuff, extent of glenoid erosion and to look for signs of humeral cup loosening. The clinical outcomes were evaluated pre- and postoperatively using the simple shoulder test (SST), DASH (Disabilities of the Arm, Shoulder and Hand) and the Constant-Murley score. Pain was estimated using a visual analog scale (VAS). The range of motion (ROM) was determined pre- and postoperatively. All patients had standard AP and lateral X-ray views of the shoulder taken as part of their postoperative follow-up protocol to look for implant loosening. RESULTS: The mean follow-up was 35.9 months (24-59±10.7). There were no intraoperative or postoperative complications. All the functional scores were improved after RSA. The median weighted Constant score preoperatively was 46% (36; 62) while it was 92% postoperatively (78; 100) (p<0.0001). The active ROM improved by 65° in forward flexion (p=0.0003) and by 30° in external rotation (p=0.002). On X-rays, we identified one patient with Sirveaux stage 4 glenoid notching and one patient with a humeral periprosthetic radiolucent line less than 2mm thick in zone 6, with no clinical consequences. CONCLUSION: The excellent outcomes after RSA for failed HHR in our study are similar to the ones reported when RSA is performed for cuff tear arthropathy.
Asunto(s)
Artroplastía de Reemplazo de Hombro/instrumentación , Hemiartroplastia/instrumentación , Cabeza Humeral/cirugía , Osteoartritis/cirugía , Falla de Prótesis , Reoperación , Prótesis de Hombro/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Artroplastía de Reemplazo de Hombro/métodos , Femenino , Estudios de Seguimiento , Hemiartroplastia/métodos , Humanos , Cabeza Humeral/diagnóstico por imagen , Cabeza Humeral/patología , Masculino , Persona de Mediana Edad , Osteoartritis/diagnóstico por imagen , Osteoartritis/patología , Radiografía , Estudios Retrospectivos , Articulación del Hombro/diagnóstico por imagen , Articulación del Hombro/patología , Articulación del Hombro/cirugía , Resultado del TratamientoRESUMEN
AIMS: To assess the extent of osteointegration in two designs of shoulder resurfacing implants. Bony integration to the Copeland cylindrical central stem design and the Epoca RH conical-crown design were compared. PATIENTS AND METHODS: Implants retrieved from six patients in each group were pair-matched. Mean time to revision surgery of Copeland implants was 37 months (standard deviation (sd) 23; 14 to 72) and Epoca RH 38 months (sd 28; 12 to 84). The mean age of patients investigated was 66 years (sd 4; 59 to 71) and 58 years (sd 17; 31 to 73) in the Copeland and Epoca RH groups respectively. None of these implants were revised for loosening. RESULTS: Increased osteointegration was measured under the cup in the Copeland implant group with limited bone seen in direct contact with the central stem. Bone adjacent to the Epoca RH implants was more uniform. CONCLUSION: This difference in the distribution of bone-implant contact and bone formation was attributed to the Epoca implant's conical crown, which is positioned in more dense peripheral bone. The use of a central stem may not be necessary provided there is adequate peripheral fixation within good quality humeral bone. TAKE HOME MESSAGE: Poor osteointegration of cementless surface replacement shoulder prosthesis may be improved by implant design.
Asunto(s)
Artroplastia de Reemplazo , Oseointegración , Articulación del Hombro/cirugía , Anciano , Densidad Ósea , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Diseño de Prótesis , Reoperación , Estudios Retrospectivos , Articulación del Hombro/patología , Factores de TiempoRESUMEN
OBJECTIVE: To assess the surgical parameters and the clinical and radiological outcomes of revisions of resurfacing shoulder arthroplasty to non-cemented short-stem reverse total shoulder arthroplasty. MATERIAL AND METHODS: A total of 23 revisions from resurfacing shoulder arthroplasty to reverse total shoulder arthroplasty were performed. The mean age was 70.3±11.95 years. The patients included 82.6% (19/23) revised for cuff failure; 13.04% (3/23) cuff failure and aseptic loosening, and 4.35% (1/23) peri-prosthetic fracture. The need for humeral osteotomy or structural allograft, operation length, blood loss, blood transfusions and intraoperative fractures were recorded. Minimum follow-up 25 months. RESULTS: No humeral osteotomy or humeral structural allograft was required, and 2/23 (8.69%) required allograft for glenoid reconstruction. The mean operation time was 113.35±21.30minutes. Intra-operative blood loss was 374±245.09 mls. Blood transfusion was required in one case. Intra-operative fracture occurred in 1 case. The Constant score improved from 17.32 to 59.78 (age/sex adjusted, 84). Overall satisfaction improved from 1.37 to 8.04. The range of motion increased 79.57° in forward elevation; 72.88° in abduction; 38.06° in internal rotation; and 13.57° in external rotation. There was no evidence of radiolucency, subsidence, or bone resorption. CONCLUSION: Revisions of resurfacing implants to non-cemented short-stem reverse prosthesis show good clinical and radiological outcomes, with minimal intra-operative complexities. LEVEL OF EVIDENCE: IV, case series.
Asunto(s)
Artroplastía de Reemplazo de Hombro/instrumentación , Reoperación/instrumentación , Prótesis de Hombro , Adulto , Anciano , Anciano de 80 o más Años , Artroplastía de Reemplazo de Hombro/métodos , Cementos para Huesos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/epidemiología , Reoperación/métodos , Estudios RetrospectivosRESUMEN
BACKGROUND: Cementless surface replacement hemiarthroplasty (CSRHA) is an established treatment for glenohumeral osteoarthritis; however, studies evaluating its role in arthritis with rotator cuff deficiency are limited. This study reviews the outcomes of CSRHA for glenohumeral osteoarthritis with and without rotator cuff tears. METHODS: 41 CSRHA (Mark III Copeland prosthesis) were performed for glenohumeral osteoarthritis with intact rotator cuffs (n = 21) and cuff-deficient shoulders (n = 20). Patients were assessed using Oxford and Constant questionnaires, patient satisfaction, range of motion measurements and by radiography. RESULTS: Mean age and follow-up were 75 years and 5.1 years, respectively. Functional gains were significantly higher in patients with intact rotator cuffs compared to cuff-deficient shoulders, with Oxford Shoulder Score improving from 18 to 37.5 and 15 to 27 and forward flexion improved from 60° to 126° and 44° to 77° in each group, respectively. Two patients with deficient cuffs had deficient subscapularis tendons; one of which was dislocated anteriorly. CONCLUSIONS: CSRHA provides significant improvements in pain and function in patients with glenohumeral osteoarthritis. In patients with deficient cuffs, functional gains are limited, and should be considered in low-demand patients where pain is the primary problem. Caution should be taken in patients with a deficient subscapularis as a result of the risk of dislocation.
RESUMEN
BACKGROUND: The present study reports our experience of Copeland shoulder cementless surface replacement arthroplasty (CSRA) and whether glenoid microfracture influences the progression of glenoid erosion. METHODS: One-hundred-and-twelve CSRAs were performed in 101 patients between 2002 and 2007. Eighty-three patients were alive at the median follow-up time of 72 months (range 9 to 121 months; interquartile range 46 to 93 months). Assessment included an Oxford shoulder score (OSS), patient satisfaction score and plain radiographs. RESULTS: The mean (range) OSS was 27 (7 to 48) and 64 of 73 (87.7%) patients were 'very satisfied' or 'satisfied' with their shoulder. Twenty-three (20.5%) shoulders had over 2 mm of glenoid erosion. Microfracture was performed in 43 of 112 shoulders (38.4%) and did not influence the progression of glenoid erosion. Further surgery was performed in 27 (24.1%) shoulders, including 15 revisions, eight arthrolyses and four subacromial decompressions. Revision to total shoulder arthroplasty was performed in 14 : 10 for glenoid erosion; one each for loosening, periprosthetic fracture, deep infection, and chronic pain. One was revised to reverse arthroplasty for chronic pain. CONCLUSIONS: CSRA performed in an independent centre reproduces the functional outcomes reported by the designer. Glenoid erosion, however, was a common occurrence and the main cause of revision - microfracture did not influence its progression.
RESUMEN
INTRODUCTION: Total shoulder resurfacing (TSR) provides a reliable solution for the treatment of glenohumeral arthritis. It confers a number of advantages over traditional joint replacement with stemmed humeral components, in terms of bone preservation and improved joint kinematics. This study aimed to determine if humeral reaming instruments produce a thermal insult to subchondral bone during TSR. PATIENTS AND METHODS: This was tested in vivo on 13 patients (8 with rheumatoid arthritis and 5 with osteoarthritis) with a single reaming system and in vitro with three different humeral reaming systems on saw bone models. Real-time infrared thermal video imaging was used to assess the temperatures generated. RESULTS: Synthes (Epoca) instruments generated average temperatures of 40.7°C (SD 0.9°C) in the rheumatoid group and 56.5°C (SD 0.87°C) in the osteoarthritis group (P = 0.001). Irrigation with room temperature saline cooled the humeral head to 30°C (SD 1.2°C). Saw bone analysis generated temperatures of 58.2°C (SD 0.79°C) in the Synthes (Epoca) 59.9°C (SD 0.81°C) in Biomet (Copeland) and 58.4°C (SD 0.88°C) in the Depuy Conservative Anatomic Prosthesis (CAP) reamers (P = 0.12). CONCLUSION: Humeral reaming with power driven instruments generates considerable temperatures both in vivo and in vitro. This paper demonstrates that a significant thermal effect beyond the 47°C threshold needed to induce osteonecrosis is observed with humeral reamers, with little variation seen between manufacturers. Irrigation with room temperature saline cools the reamed bone to physiological levels and should be performed regularly during this step in TSR.