Tuesday, July 28, 2015

Results of attempted arthroscopic cuff repair - do articles like this make us any smarter?

Prognostic factors for recovery after arthroscopic rotator cuff repair: a prognostic study

These authors studied a series of 30 patients having attempted arthroscopic rotator cuff repair using the Western Ontario Rotator Cuff Index as primary outcome and RAND-36, Constant-Murley score, and a shoulder hindrance score as secondary outcomes. The characteristics of the rotator cuffs are shown below

Patients were significantly improved at 3 months and 6 months after arthroscopic rotator cuff repair. In multiple regression analysis, no factors could be identified as prognostic of the quality of life after arthroscopic rotator cuff repair (measured with the Western Ontario Rotator Cuff Index). For the outcome variables RAND-36 (6 months, 1 year) and shoulder hindrance score (1 year), fatty infiltration Goutallier stages 1 and 2 and retraction grades II, III, and IV were significant predictors.



Comment:  
What can be learned from this small series is that the recovery after attempted cuff repair is progressive over the first year, with only 50% of the functional recovery having been achieved at 3 months. This is important in light of the article that assumed that workers would be back to work 28 days after attempted cuff repair.

In this study, no followup cuff imaging was performed, so the rate of failure of the repair and the relationship of repair failure to clinical outcome are unknown. 

A comprehensive analysis on the effect of prognostic factors on clinical outcomes and cuff integrity is discussed in this post.

====

Use the "Search" box to the right to find other topics of interest to you.


You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and runreverse total shoulderCTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'


Monday, July 27, 2015

Why are we still using the term 'impingement syndrome'?

Medium-term natural history of subacromial impingement syndrome

In their introduction these authors state, "Subacromial impingement syndrome (SIS) is the most frequently reported diagnosis of the shoulder, with a cumulative incidence of 5 per 1,000 patients per year.  SIS is a spectrum of diseases that range from tendinitis to partial or full-thickness rotator cuff tears that affect the daily overhead activities of patients."  For 63 patients two whom they attached the diagnosis of subacromial impingement syndrome, the authors recorded age, gender, profession, body mass index, hand dominance, alcohol and tobacco consumption, comorbidities, causative event of pain, presence of a functional limitation, duration of symptoms, shoulder scores, history of subacromial steroid injections, and magnetic resonance imaging (MRI) classification.

They found that younger age, lower BMI, more functional capacity, a shorter symptomatic period, reversible changes on MRI, and higher Constant and ASES scores at the first evaluation were associated with a better outcomes - that is, healthier, younger patients with less severe disease had better shoulder function 8.5 years later.

Comment: With respect to the term 'impingement syndrome' we have pointed out previously that using the current tools of history, physical examination, and rotator cuff imaging, surgeons should have no difficulty in distinguishing tendinitis from a partial cuff tear and a partial from a full thickness cuff tear. To lump these conditions - each of which affects different groups of patients and has different treatments - together, is like mixing osteoarthritis, rheumatoid arthritis and avascular necrosis under the term 'shoulder arthritis'. The fact that each of the conditions may respond to a subacromial lidocaine injection does not help in defining the pathology.

Natural history studies are studies of the untreated course of a disease. The authors state that this is a 'natural history' study, but it is not clear which of these patients received what treatment except for the statement,  "Seven patients underwent surgical treatment because of a chronic course that did not improve with conservative treatment."

Without clearer definition of the diagnoses and the treatments, we can only conclude that younger, healthier patients with less severe involvement have better function later on.

===

Check out the new Shoulder Arthritis Book - click here.



Use the "Search" box to the right to find other topics of interest to you.

You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and runreverse total shoulderCTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'







Rotator cuff repair - what is an 'early repair' of an "acute" rotator cuff tear?

Surgery within 6 months of an acute rotator cuff tear significantly improves outcome

These authors performed a retrospective analysis of patients having sustained an acute full-thickness rotator cuff tear defined as a sudden episode of shoulder pain precipitated by a traumatic episode resulting in a deterioration in shoulder function with self-reported normal shoulder function before injury. 

 Twenty had rotator cuff repair within 6 months of injury - these were compared to 20 age- and sex-matched patients who had undergone delayed repair (6-18 months after injury; mean age, 60 years; age range, 40-78 years). The mean follow-up period was 10 months for the early repair group versus 11 months for the delayed repair group. Both groups had clinically significant improvements in their Oxford scores, although the early repair group had an improvement that was nearly double that of the delayed repair group (20.3 for early vs 10.4 for delayed, P = .0014). Postoperative Oxford scores were significantly higher in the early repair group (mean of 43.8 for early vs 35.8 for delayed, P = .0057). There were 2 symptomatic retears in the early repair group versus 5 in the delayed repair group.


Comment: A few comments about this study:
(1) patients with 'self-reported normal shoulder function' can have asymptomatic tears - many of the 60 year old patients in this study are likely to have had some degree of degenerative tearing, so it is difficult to distinguish an acute tear from an acute extension of a chronic tear
(2) the definition of a 'traumatic episode' can vary substantially from lifting a suitcase to falling off a ski lift
(3) one cannot use the rate of 'symptomatic retears' as an indication of the success rate of repair - many retears are asymptomatic so that the the retear rate can only be known if a standardized imaging protocol is applied.
(4) 'matching' groups of patients is tenuous unless we know the degree of trauma, the surgeons, techniques, and other factors such as smoking history for both groups.
(5) repair at 6 months is not really an 'early repair. 

Nevertheless it makes sense that tendon ruptures are more amenable to successful reconstitution if the repair is performed immediately after the injury. What surgeon would wait 6 months, or even one month to repair the rupture of a quadriceps tendon? Why is the shoulder different?

Our practice is to treat the acute onset of weakness after a substantial injury in a healthy individual as an indication for urgent imaging of the rotator cuff using MRI or sonography. By urgent we mean within a week - it is intuitive that the quality of the tendon, muscle and bone as well as the degree of retraction will worsen progressively from the time of injury.  If the history, physical examination and cuff imaging together suggest an acute reparable rotator cuff tear, our goal is to discuss with the patient an expeditious attempt at repair within a month of the injury.

Click here to see the Rotator Cuff Tear Book

====

Use the "Search" box to the right to find other topics of interest to you.


You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and runreverse total shoulderCTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'






Sunday, July 26, 2015

Reverse total shoujder - effects of lateralization of the center of rotation

The effects of progressive lateralization of the joint center of rotation of reverse total shoulder implants.

These authors used a 3-dimensional model to explore the effects of lateralizing the center of rotation (CoR) on the deltoid muscle moment arm and glenohumeral joint contact forces. This model was virtually implanted with 5 progressively lateralized reverse shoulder prostheses. The joint contact loads and deltoid moment arms were calculated for each lateralization over the course of 3 simulated standard humerothoracic motions.

In this model, lateralizing the CoR led to an increase in the overall joint contact forces across the glenosphere. Most of this increased loading occurred through compression, although increases in anterior/posterior and superior/inferior shear were also observed. Moment arms of the deltoid consistently decreased with lateralization. Bending moments at the implant interface increased with lateralization. Progressive lateralization resulted in improved stability ratios.

Comment: These observations are important, but they are also predictable from from a free body diagram (as suggested by the illustration by Steve Lippitt below). When the center of rotation is moved laterally (as in the diagram to the right), the deltoid force becomes increasingly effective in pressing the glenosphere and the humeral cup together, increasing the contact force and the stability by the concavity compression mechanism. The deltoid moment arm is decreased by lateralization (note the change in the distance between the dot at the CoR and the red deltoid muscle). The bending moment at the implant interface (the distance between the dot and the face of the glenoid bone) is increased by lateralization.
The additional benefit of lateralization - distancing the medial humeral component from the lateral glenoid neck - is also seen on these diagrams.


====

Use the "Search" box to the right to find other topics of interest to you.

You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and runreverse total shoulderCTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'







Reverse total shoulder - lateral offset of the glenoid component - is bone graft best?

Bony Increased-Offset Reverse Shoulder Arthroplasty

In the abstract of this article, the authors state "Reverse shoulder arthroplasty has proven useful in numerous pathologic conditions, such as that of pseudoparalytic shoulder with severe rotator cuff deficiency with or without collapse (so-called cuff-tear arthropathy), rheumatoid arthritis, dislocations and sequelae of proximal humerus fractures, and revision shoulder arthroplasty. Despite the advances beyond the constrained reverse prostheses of the 1970s resulting from Grammont’s principles, problems remain with current systems, with high rates of scapular notching and prosthetic instability. Lateralization of the center of rotation of the shoulder joint has been viewed as a potential solution to these persistent problems, and is included in the procedure known as bony increased-offset reverse shoulder arthroplasty. This article presents our surgical technique for this procedure and promising early results of its use." The article itself is elegantly presented by the highly experienced shoulder surgeon who has exhibited mastery of this method.

The authors performed a prospective study in 42 patients with rotator cuff deficiency to determine whether BIO-RSA would avoid the problems caused by humeral medialization. At a minimum follow-up of 2 years (average, 28 months), 39 of 42 patients (93%) were satisfied or very satisfied with its functional results; 32 of the 42 patients (76%) had good or excellent adjusted Constant-Murley scores. There were no cases of loosening of the glenoid component of the prosthesis. The graft bone used with the prosthesis was observed to have healed to the glenoid in 41 of the 42 patients (98%) on follow-up examination with radiography and CT scanning. Scapular notching occurred in 19% (8 of 42) of the patients. There were no instances of instability of the prosthesis and no instances of reoperation.

Comment: In the early days of the reverse, surgeons avoided lateral offset because of concerns about the loosening moments applied to the glenosphere and a desire to optimize the deltoid moment arm. However, medial placement of the glenosphere is now recognized to risk contact between the medial aspect of the humeral component and the inferior glenoid which can lead to notching and instability. As a result, surgeons are using one of two methods for lateralizing the center of rotation: 
(1) the bony increased-offset reverse shoulder arthroplasty described in this article


and (2) glenoid components with a built-in lateral offset. 




In both instances, the lateralized center of rotation places additional demands on the fixation of the glenoid component to the scapula. Our preference is for glenoid components with a built-in lateral offset as described here and here because (a) the fixation does not depend on healing of a bone graft, (b) the quality of bone available for a bone graft is variable in patients having primary reverse total shoulders, (c) bone graft from the humeral head is not available in revision arthroplasty, (d) the operative time and special instruments for bone graft harvest are eliminated and (e) the central screw can be tightened to compress the glenoid component on the bone of the glenoid without worry of crushing the graft.

====

Use the "Search" box to the right to find other topics of interest to you.

You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and runreverse total shoulderCTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'


Reverse total shoulder arthroplasty - failure and revision - cautionary tale!

Failure after reverse total shoulder arthroplasty: what is the success of component revision?

These authors performed 228 reverse total shoulders over the study periord. 17 had revision surgery - one passed away. They were able to review 16 of these patients having component revision after failure of a prior reverse total shoulder arthroplasty (RTSA). Their overall rate of reoperation was 10% with 7.5% needing component revision. Nine patients had complications of their revision RTSA (persistent instability, failure of baseplate, infection, screw impingement, periprosthetic humeral fracture and glenoid fracture).

Original components for the index RTSA included the Zimmer Anatomical Reverse in 10, Tornier Aequalis in 4  and DePuy Delta III in 2 shoulders.

Seven had failure of the baseplate - three of these revisions failed.

Six had instability - three of these revisions failed.

Two had infection - both required multiple procedures

One had humeral component loosening - the functional results and radiographic results were 'less than ideal'

While overall the patients were improved, nine patients suffered major complications 6 ultimately underwent further procedures.

Comment: In the hands of these expert surgeons, the overall revision rate was 8%. Baseplate failure, instability and infection were the major issues.

 



We have attempted to minimize the risk of these complications by assuring excellent purchase of the baseplate by strong glenoid fixation screws and by East-West tensioning of the soft tissues as described in this link and here.

===

Check out the new Shoulder Arthritis Book - click here.



Use the "Search" box to the right to find other topics of interest to you.

You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and runreverse total shoulderCTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'




Saturday, July 25, 2015

Arthroscopic patch autograft procedure for large to massive rotator cuff tears - are we asking the right question?

Effect of Fatty degeneration of the infraspinatus on the efficacy of arthroscopic patch autograft procedure for large to massive rotator cuff tears.

These authors investigated the results of an arthroscopic fascia lata autograft patch procedure in 45 patients with large to massive rotator cuff tears with high-grade fatty degeneration of the supraspinatus and either low-grade (group L; n=26) or high-grade (group H; n=19) fatty degeneration of the infraspinatus.

Patients in group L had a lower rate of failed repairs (27%) than did those in group H (89%)  as assessed by MRI. The clinical outcome scores and muscle strength ratios were significantly higher in group L than in group H. 

Comment: It is not surprising that patients with more severe cuff disease (high-grade fatty degeneration of both the supraspinatus and the infraspinatus) did more poorly than those with less severe disease (high-grade fatty degeneration of the supraspinatus and low grade fatty degeneration of the infraspinatus). The rate of failure of the repair attempt was high in both groups - even in the 'low grade' group, more than one out of four repairs failed.

The question we should be asking is "what is the value of the arthroscopic patch"? In other words is the improvement in the anatomic and clinical outcomes with this repair technique sufficient to offset the incremental cost and risk of this procedure in comparison to simpler strategies

Should we be trying to repair the irreparable?

====

Use the "Search" box to the right to find other topics of interest to you.


You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and runreverse total shoulderCTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'