Dr Michell Ruiz

Dr Michell Ruiz
Cirugía de hombro y del Manguito rotador

domingo, 19 de octubre de 2014

Shoulder Bursitis Symptoms


Conversion of an anatomic to a reverse total shoulder, when is a 'platform' prosthesis of benefit? Reprise

http://shoulderarthritis.blogspot.mx/2014/10/conversion-of-anatomic-to-reverse-total.html


Conversion of an anatomic to a reverse total shoulder, when is a 'platform' prosthesis of benefit? Reprise

Due to the great interest in this subject, we're repeating this post with some additional thoughts.

An anatomic arthroplasty can fail for many reasons, including malposition, instability, delayed cuff failure and pseudo paralysis. In these situations consideration can be given to conversion of the anatomic prosthesis to a reverse total shoulder as shown here. As demonstrated in that post out preferred method for managing a failed anatomic arthroplasty is to completely remove the existing implant, obtain cultures, and then implant the reverse prosthesis. This approach allows full access to the glenoid and optimal positioning of the humeral component of the reverse. Removal of the anatomic implant is almost always possible and is particularly straightforward if it was inserted using impaction grafting.

In certain cases, such as that shown here, a well fixed stem can be retained and the proximal end converted to a reverse total shoulder with insertion of a glenosphere. Here's another post regarding conversion with retention of the anatomic stem.

Recently, there has been the advent of 'platform' prostheses, in which a humeral stem is fixed in the humeral canal that can be attached to either an anatomic or a reverse proximal humeral prosthesis. For examples, see hereherehere, and here.

It is important to recognize that in a reverse, (1) the glenosphere is placed inferiorly on the glenoid face, (2) the proximal humeral part of the reverse is bigger than that of an anatomic humeral arthroplasty and (3) the soft tissue tensioning considerations of a reverse are different from those of an anatomic arthroplasty. Therefore, the proximal-distal positioning of the humeral component needs to be fine tuned to achieve the ideal reverse arthroplasty. While some systems provide various adaptors to adjust the height, inclination and version of the proximal humeral prosthesis, the flexibility in positioning is limited by the use of the 'platform' fixed in the humeral canal.

Fortunately, we now have a clearer understanding of the indications for a reverse total shoulder, so that the needs for convertible prostheses is diminishing. For example, it is becoming evident that proximal humeral fractures in elderly individuals are often best managed by a primary reverse total shoulder - the idea of 'trying' an anatomic arthroplasty that is convertible to a reverse later is not so appealing. Similarly, individuals with arthritis, cuff deficiency, and instability are also best managed by a primary reverse.

See related post here.

One of the aspects lacking in articles about platform and other types of new shoulder prostheses is the incremental cost of the implant. This information is necessary to determine the value (benefit/cost) of the device. The question becomes, for 100 anatomic arthroplasties, how many successful conversions to reverses would be necessary to justify the incremental cost of (1) the implant and (2) the learning curve?

In our practice, revision of an anatomic to a reverse prosthesis is required almost exclusively in cases where the index procedure is done elsewhere. Often there are problems with stem fixation or positioning that require stem removal, even if 'in theory' the platform stem is convertible to a reverse.

One of the advantages of fixation of a humeral stem with impaction grafting is that - should conversion to a reverse prosthesis be required - the stem can be easily removed and the reverse stem inserted at the desired height and version.

martes, 14 de octubre de 2014

Evita el dolor del hombro tonificando el manguito rotador

http://www.angelvillamor.com/2010/01/evita-el-dolor-del-hombro-tonificando.html


Evita el dolor del hombro tonificando el manguito rotador



En nuestra consulta tenemos la oportunidad de ver a bastantes pacientes que acuden quejándose de un dolor de origen inespecífico en el hombro. No han tenido traumatismos, no han sufrido ningún tipo de accidente y tampoco han llevado a cabo esfuerzos que expliquen estas molestias que, sin embargo, merman su calidad de vida.

El dolor suele aparecer en la parte frontal o externa del hombro y empeora cuando se levanta el brazo o se sostiene algo por encima de la cabeza. La intensidad de las molestias puede llegar al extremo de no poder hacer este tipo de movimientos o de despertar al paciente por la noche.

La explicación mecánica para este trastorno es que existe un compromiso delespacio subacromial, el lugar por el que discurren una serie de tendones que componen el llamado manguito rotador, un conjunto musculotendinoso encargado de darle estabilidad al hombro y de facilitar el movimiento circular de esta zona

En esta articulación se encuentran la escápula (omóplato) y el húmero (el hueso que va desde el codo hasta el hombro). Ambos huesos no se juntan en los extremos manteniéndose en una posición perfecta como ocurre en otras zonas del aparato locomotor, ni están sujetos mediante ligamentos.

Por lo tanto, para garantizar el correcto funcionamiento de dicha articulación es necesaria la intervención de una serie de músculos que conectan ambos huesos y sus correspondientes tendones.

Ese entramado constituyen el citado manguito rotador que, en realidad, no es más que un cilindro que envuelve la articulación para ‘amarrarla’ a la cabeza del húmero.

Procedimientos quirúrgicos

Hace años, en iQtra aprendimos una serie de técnicas quirúrgicas y fisioterapéuticas (cirugía artroscópica tanto descompresiva como reparadora) adecuadas para tratar este problema. Para ello, recurrimos a escuelas estadounidenses ya que los traumatólogos norteamericanos estaban más experimentados en su tratamiento.

El motivo no es otro que una mayor tradición en aquel país en la práctica de deportes como el baseball, que requieren lanzamientos repetitivos que dañan esta zona con relativa facilidad.

A lo largo de esta década hemos adquirido la suficiente casuística como para darnos cuenta de que gran parte de estas tendinitis que afectan al hombro no son consecuencia únicamente de la sobrecarga deportiva o profesional.

También nos encontramos muchos casos radicalmente opuestos. Es decir,tendinitis ocasionadas por la debilidad de la musculatura estabilizadora de los pacientes sendentarios.

En estos individuos, los tendones que conforman el manguito rotador están tan desentrenados que precisamente la falta de tono (que es lo que contribuye a dar firmeza y estabilidad a toda la articulación) es lo que provoca la aparición deirritaciones tendinosas que acaban degenerando en una tendinitis en toda regla, y no precisamente por un exceso de esfuerzo físico.

Evitar el quirófano con ejercicios

Por este motivo, en iQtra estamos poniendo especial empeño en aleccionar a nuestros pacientes, así como a preparadores físicos, entrenadores y médicos deportivos de nuestro entorno para que procuren mantener un buen tono de las estructuras del manguito rotador.

Estos protocolos, denominados recentraje de cabeza del húmero constan de una serie de ejercicios específicos que contribuyen a prevenir la tendinitis. Si se practican de una forma más o menos regular, en ocasiones desaparece la necesidad de pasar por el quirófano (un motivo muy frecuente de consulta por este motivo).
En realidad, estos ejercicios son los mismos que se emplean en la recuperación que se lleva a cabo después de la cirugía. Ciertamente, a veces ésta es inevitable, pero estamos tratando de que estos ejercicios se introduzcan en las rutinas de preparación física para reducir drásticamente no sólo el número de intervenciones quirúrgicas, sino las tendinitis derivadas de la inestabilidad articular secundaria a la debilidad de los tendones del manguito rotador.

Featured Surgery on ICJR.net: Primary Reverse Total Shoulder Arthroplasty with Patient-specific Instrumentation

http://myemail.constantcontact.com/Featured-surgery--Reverse-total-shoulder-arthroplasty.html?soid=1108504812258&aid=z6ZmUaZtJNE





domingo, 12 de octubre de 2014

Conversion of anatomic arthroplasty to reverse total shoulder: what is the place for modular stems?

http://shoulderarthritis.blogspot.mx/2014/10/conversion-of-anatomic-arthroplasty-to.html


Sunday, October 12, 2014

Conversion of anatomic arthroplasty to reverse total shoulder: what is the place for modular stems?

Conversion of Stemmed Hemi- or Total to Reverse Total Shoulder Arthroplasty: Advantages of a Modular Stem Design

These authors point out that revision of a well-fixed humeral stem has the potential risk of loss of humeral bone stock, nerve injury, periprosthetic fracture, and malunion or nonunion of a humeral osteotomy with later humeral component loosening.

They conducted a retrospective study of 48 hemiarthroplasties and eight total shoulder arthroplasties that were converted to a reverse total shoulder arthroplasty system. 
The commonest reasons for conversion to a reverse shoulder arthroplasty was rotator cuff lesion with instability/loss of function (29), aseptic stem loosening (8), stem malposition with functional deficit (8), failure of glenoid component (6), and glenoid erosion (5). 

In 13 cases (all with modular stems) the surgeon elected retain the humeral stem and in 43 (6 with modular stems and 37 without modular seems) the surgeon elected to change the stem because of stem loosening in 10 cases, stem malposition in 8, and difficulty in conversion of a non modular stem to a reverse in 25. In 12 cases a longitudinal humeral osteotomy was required for stem removal.

Blood loss, surgical time, the rate of complications (principally fractures) and revision rate were greater in the cases where the surgeon chose to perform a full stem exchange. 


Comment: It is of interest that most of the anatomic hemiarthroplasties and total shoulder arthroplasties in this series that were revised to reverse total shoulders were for diagnoses (proximal humeral fractures, post traumatic arthritis and cuff tear arthropathy) that today may well be treated with primary reverse total shoulders rather than an anatomic arthroplasty with a modular stem.

Conversion of a failed hemiarthroplasty for fracture to a reverse total shoulder

http://shoulderarthritis.blogspot.mx/2014/10/conversion-of-failed-hemiarthroplasty.html


Thursday, October 2, 2014

Conversion of a failed hemiarthroplasty for fracture to a reverse total shoulder

An elderly patient had a hemiarthroplasty for fracture one year ago.  She presented to our clinic with pain and instability. On exam she had anterior superior escape and pseudoparalysis. She desired revision to a reverse total shoulder.




The long humeral stem was well fixed with a large cement mantle. Removal of this stem from her thin bone would require a humeral osteotomy as shown here which would have complicated the stabilization of the humeral component of a reverse humeral component.

Thus, our plan was to try to preserve the stem and convert it to a reverse. Antibiotics were held for cultures, although there was no obvious evidence of gross infection. The humeral head was removed and the modular collar was removed. The humeral stem was well fixed.

There was significant scar tissue present in the wound limiting access to the glenoid. The soft tissue around the proximal humerus was released circumferentially and released from the inferior glenoid to gain excursion of the humerus distally. This exposure was difficult because of the fixed prominence of the humeral prosthesis.

The native glenoid was covered in fibrous tissue, which was debrided and reamed to a stable base.

One the exposure was sufficient, the glenoid component was inserted followed by the proximal humeral component of the reverse. We were fortunate that the shoulder could be stably reduced.

The patient is placed on the yellow protocol until culture results are final. Exercises will be started after six weeks of sling immobilization.
Comment: As we pointed out two blog posts ago, this case points out that the need for difficult conversion can often be avoided by performing a primary reverse for major displaced fractures of the proximal humerus in older individuals if the tuberosities cannot be stably reconstructed - obviously the case here. A second point is that conversion without humeral component removal is desirable, but difficult and the success of the conversion depends on being fortunate enough to have soft tissue balance without flexibility in the placement of the humeral and glenoid components of the reverse.
Finally, revision surgery of this type requires the surgeon to become familiar with arthroplasty systems foreign to his/her practice. There were many nuances of this prosthesis that we had to learn 'on the fly'.

Prepared by Robert Lucas, M.D.

miércoles, 8 de octubre de 2014

What Are Shoulder Problems?