Limits...
Prosthesis design and placement in reverse total shoulder arthroplasty.

Ackland DC, Patel M, Knox D - J Orthop Surg Res (2015)

Bottom Line: The management of irreparable rotator cuff tears associated with osteoarthritis of the glenohumeral joint has long been challenging.Clinical and biomechanical studies have revealed that component design and placement affects the location of the joint centre of rotation and therefore the force-generating capacity of the muscles and overall joint mobility and stability.Furthermore, surgical technique has also been shown to have an important influence on clinical outcome of RSA, as it can affect intra-operative joint exposure as well as post-operative muscle function.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, University of Melbourne, Parkville, Victoria, 3010, Australia. dackland@unimelb.edu.au.

ABSTRACT
The management of irreparable rotator cuff tears associated with osteoarthritis of the glenohumeral joint has long been challenging. Reverse total shoulder arthroplasty (RSA) was designed to provide pain relief and improve shoulder function in patients with severe rotator cuff tear arthropathy. While this procedure has been known to reduce pain, improve strength and increase range of motion in shoulder elevation, scapular notching, rotation deficiency, early implant loosening and dislocation have attributed to complication rates as high as 62%. Patient selection, surgical approach and post-operative management are factors vital to successful outcome of RSA, with implant design and component positioning having a significant influence on the ability of the shoulder muscles to elevate, axially rotate and stabilise the humerus. Clinical and biomechanical studies have revealed that component design and placement affects the location of the joint centre of rotation and therefore the force-generating capacity of the muscles and overall joint mobility and stability. Furthermore, surgical technique has also been shown to have an important influence on clinical outcome of RSA, as it can affect intra-operative joint exposure as well as post-operative muscle function. This review discusses the behaviour of the shoulder after RSA and the influence of implant design, component positioning and surgical technique on post-operative joint function and clinical outcome.

No MeSH data available.


Related in: MedlinePlus

Grade 4 notching with osteolysis resulting in glenoid loosening (a), the original polyethylene humeral liner component (b) and the same humeral liner component retrieved after notching and glenoid loosening (c)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4493953&req=5

Fig4: Grade 4 notching with osteolysis resulting in glenoid loosening (a), the original polyethylene humeral liner component (b) and the same humeral liner component retrieved after notching and glenoid loosening (c)

Mentions: Medialisation of the reverse prosthetic glenohumeral joint may lead to scapular impingement or ‘notching’. Scapular notching refers to the gradual erosion of the scapular neck inferior to the peg or geometric centre of the glenoid implant. This is considered to be a result of direct mechanical abutment of the polyethylene humeral tray against the scapular neck as the arm is placed in adduction. Scapular notching, which has been reported in up to 80 % of cases [16, 47], is frequently graded using Sirveaux’s classification [20] (Fig. 3). Of particular concern is grade 4 notching (up to the inferior screw and glenoid peg) which may result in glenoid loosening (Fig. 4). Ultimately, scapular notching resulting in adduction deficit has the potential to generate polyethylene wear debris which can stimulate osteolysis [48]. This has prompted significant implant design modification and surgical technique review.Fig. 3


Prosthesis design and placement in reverse total shoulder arthroplasty.

Ackland DC, Patel M, Knox D - J Orthop Surg Res (2015)

Grade 4 notching with osteolysis resulting in glenoid loosening (a), the original polyethylene humeral liner component (b) and the same humeral liner component retrieved after notching and glenoid loosening (c)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4493953&req=5

Fig4: Grade 4 notching with osteolysis resulting in glenoid loosening (a), the original polyethylene humeral liner component (b) and the same humeral liner component retrieved after notching and glenoid loosening (c)
Mentions: Medialisation of the reverse prosthetic glenohumeral joint may lead to scapular impingement or ‘notching’. Scapular notching refers to the gradual erosion of the scapular neck inferior to the peg or geometric centre of the glenoid implant. This is considered to be a result of direct mechanical abutment of the polyethylene humeral tray against the scapular neck as the arm is placed in adduction. Scapular notching, which has been reported in up to 80 % of cases [16, 47], is frequently graded using Sirveaux’s classification [20] (Fig. 3). Of particular concern is grade 4 notching (up to the inferior screw and glenoid peg) which may result in glenoid loosening (Fig. 4). Ultimately, scapular notching resulting in adduction deficit has the potential to generate polyethylene wear debris which can stimulate osteolysis [48]. This has prompted significant implant design modification and surgical technique review.Fig. 3

Bottom Line: The management of irreparable rotator cuff tears associated with osteoarthritis of the glenohumeral joint has long been challenging.Clinical and biomechanical studies have revealed that component design and placement affects the location of the joint centre of rotation and therefore the force-generating capacity of the muscles and overall joint mobility and stability.Furthermore, surgical technique has also been shown to have an important influence on clinical outcome of RSA, as it can affect intra-operative joint exposure as well as post-operative muscle function.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, University of Melbourne, Parkville, Victoria, 3010, Australia. dackland@unimelb.edu.au.

ABSTRACT
The management of irreparable rotator cuff tears associated with osteoarthritis of the glenohumeral joint has long been challenging. Reverse total shoulder arthroplasty (RSA) was designed to provide pain relief and improve shoulder function in patients with severe rotator cuff tear arthropathy. While this procedure has been known to reduce pain, improve strength and increase range of motion in shoulder elevation, scapular notching, rotation deficiency, early implant loosening and dislocation have attributed to complication rates as high as 62%. Patient selection, surgical approach and post-operative management are factors vital to successful outcome of RSA, with implant design and component positioning having a significant influence on the ability of the shoulder muscles to elevate, axially rotate and stabilise the humerus. Clinical and biomechanical studies have revealed that component design and placement affects the location of the joint centre of rotation and therefore the force-generating capacity of the muscles and overall joint mobility and stability. Furthermore, surgical technique has also been shown to have an important influence on clinical outcome of RSA, as it can affect intra-operative joint exposure as well as post-operative muscle function. This review discusses the behaviour of the shoulder after RSA and the influence of implant design, component positioning and surgical technique on post-operative joint function and clinical outcome.

No MeSH data available.


Related in: MedlinePlus