Monday, August 2, 2021

Anatomic and reverse total shoulder arthroplasty: over one third of patients are obese - does this matter?

 Effects of Obesity on Clinical and Functional Outcomes Following Anatomic and Reverse Total Shoulder Arthroplasty

These authors identified 1520 patients having primary anatomic (aTSA) arthroplasty and 2054 patients having primary reverse total shoulder arthroplasty with a minimum follow-up of 2 years (mean 5 years). All patients received the same platform shoulder prosthesis. 


Patients were stratified according implant type (anatomic or reverse), and further stratification was based on patient BMI, with obese patients having a BMI ≥ 30 kg/mand non-obese patients with a BMI <30 kg/m2


Obsesity is common among patients having elective arthroplasty: 41% of aTSA and 35% of rTSA were obese. 


Obese patients in both groups reported higher preoperative and postoperative visual analog scale (VAS) pain scores (i.e. more pain) and less preoperative and postoperative ROM compared to non-obese patients. 



Compared to non-obese patients, obese patients receiving an aTSA reported significantly worse postoperative SST, Constant, ASES, UCLA, and SPADI scores compared to non-obese patients, and those receiving rTSA reported significantly worse ASES and SPADI scores. However, these

22 differences did not exceed the minimal clinical important difference (MCID) or substantial  benefit (SCB) criteria. 






Statistically significant  differences between obese and non-obese groups were not found to be clinically relevant given  that the differences between the two groups with regards to VAS pain scores, ROM, and functional outcome scores did not exceed the MCID and SCB criteria in both the aTSA and rTSA groups.


Radiographic analysis 23 showed that in rTSA, obese patients had significantly less postoperative scapular notching and a lower scapular notching grade when compared to non-obese patients (P<0.05).


Obese patients had more comorbidities, greater intraoperative blood loss.


Overall complication rates were similar between obese and non-obese groups for both aTSA (7.6% vs. 8.4%; p = 0.57) and rTSA (3.4% vs. 3.9%), including rotator cuff tears, instability, infection, component loosening or failure, dislocation, liner dissociation, stress fracture, neurological complaints, and pain. Revision rates secondary to these complications were also similar between obese and non-obese groups for both aTSA (5.1% vs  5.9%) and rTSA (2.1% vs. 1.7%).


One of the more interesting findings in this study was that obesity seemed to protect patients against scapular notching and a higher notching grade. It seems possible that obesity limited adduction of the arm, reducing the contact between the medial edge of the humeral cup and the lateral scapular neck.


While obesity is commonly listed as a "modifiable" risk factor for shoulder arthroplasty outcomes, to our knowledge no study has demonstrated improved outcomes in patients who have "modified" their BMI. 


It seems that obesity is less of a concern in shoulder arthroplasty than in hip and knee arthroplasty, yet we take extra time to discuss with these patients the need for extra attention to skin care (in the axilla and underneath the breast) and to care to protect the arm after surgery. 


How you can support research in shoulder surgery Click on this link.

Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The total shoulder arthroplasty (see this link).
The ream and run technique is shown in this link.
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
Shoulder rehabilitation exercises (see this link).
Follow on twitter: Frederick Matsen (@shoulderarth)

Saturday, July 31, 2021

Complications and recurrence of periprosthetic infections treated with two stage revision

 Midterm results of two-stage revision surgery for periprosthetic shoulder infection

These authors sought to determine the recurrent infection rate and clinical outcomes of two-stage revision for shoulder periprosthetic infection (PSI). 


A minimum of 5 white blood cells per high-powered field (40 times magnification) was considered diagnostic for infection.


They identified 17 patients ( Mean patient age was 64±7 years, and 65% of patients were male) that met this criterion for infection after shoulder arthroplasty who were treated with a two-stage revision and had a minimum followup of 5 years (range, 5-9 years). 


As shown below, among the 17 cases, Cutibacterium was recovered from tissue samples in 6, 5 cases had negative cultures, 2 had positive cultures for MSSA, 1 for MRSA, and 1 each for enterococcus, pseudomonas, and peptostreptococcus. 














The mean time from the involved arthroplasty to first stage revision was 40 months. 


All patients were revised to a reverse shoulder arthroplasty at the second-stage revision. 


All patients were treated with culture-specific antibiotics chosen in consultation with an infectious disease specialist, and treatment was individualized according to the virulence of the organism and  general health and immunity of the patient.


The decision to re-revise for reinfection was based on various factors, including chronic, recurrent pain, wound drainage, elevated ESR and CRP, loosening of humeral or glenoid components, elevated synovial cell counts on aspiration, and positive cultures at second-stage revision or subsequent aspiration. A recurrent infection was diagnosed in 3 (18%) of the 17 patients. The cumulative incidence of recurrence of infection was 0% at 1 year, 6% at 2 years, and 18% at 5 years. There were 6 (36%) other complications, including 4 periprosthetic fractures, 1 spacer fracture, and 1 dislocation. 


At latest followup, patients who did not have recurrent infection had a statistically and clinically meaningful improvement from preoperative to postoperative PROs, including VAS for pain, ASES score, SST score, and WOOS score, and active ROM, including abduction and forward flexion. 


Comment: This paper demonstrates the challenges in diagnosing and managing shoulder periprosthetic infections. Here are of few:


(1) It is recognized that Cutibacterium is the most common causative organism for shoulder PJI, yet the presentation of PJI from this organism is often subtle and delayed with non-specific symptoms of pain and stiffness. Many of these cases may escape diagnosis either because a revision is not performed or because adequate sampling and culturing of deep tissue and explant specimens is not performed at revision. The stealth presentation of Cutibacterium PJI also creates a problem when evaluating the outcome of treatment for PJI. While a failure can be diagnosed if multiple cultures from a re-revision are positive, it is difficult to define a successful revision (note that in this paper the incidence of diagnosed infection increased by 300% between the second and the fifth year after the first revision - when is the patient "out of the woods"?). 


(2) The post-revision treatment included "culture-specific antibiotics", however the outcome of cultures for Cutibacterium are not final until weeks after surgery; furthermore almost 1/3 of the cases had negative cultures. Thus the immediate postoperative antibiotic management cannot be based on culture results.


(3) It is not known how many patients planned for a two-stage revision did not proceed with the second stage. In this report three patients had a "permanent" spacer placed.


(4) While all the patients in this series were treated with two-stage revision to reverse total shoulder, the simpler and safer single stage revision to a hemiarthroplasty has been demonstrated to be effective in those cases of Cutibacterium PJI without a draining sinus (see this link and this link).


(5) What about "culture negative 'infections'"? The one case example presented in this paper showed high placement of the humeral component with rocking horse loosening of the glenoid component (see below).  



The culture results for this case are not presented. If this case was "culture negative" it might have been a case of detritic synovitis rather than infection, as described below.

Detritic synovitis can mimic a Propionibacterium periprosthetic infection This paper illustrates that the clinical findings of detritic synovitis (the macrophage reaction to polyethylene, cement or metal debris) complicating a total shoulder arthroplasty can strongly resemble those of a ‘stealth’ periprosthetic shoulder infection with a low-virulence organism such as Cutibacterium, including a clinical presentation long after the index procedure. At present, the important differentiation between these two etiologies can only be ascertained by awaiting the results of cultures obtained at the time of revision surgery. The surgical and antibiotic treatment decisions must be made before the culture results become available.

A 76-year-old right hand dominant man presented with right shoulder pain and decreased range of motion. He had a history of bilateral total shoulder arthroplasties, his left 15 years prior and his right 14 years prior to his visit with us. Following his index surgeries he initially did well with full painless range of motion and was able to return to full activities. Eleven years after his right arthroplasty he experienced the insidious onset of worsening shoulder pain and stiffness with no known injury. He also noted painful catching and locking in his shoulder joint with certain shoulder movements. His symptoms were unresponsive to non-operative treatment, including exercises, anti-inflammatory medications and a corticosteroid injection. His left shoulder had some stiffness but was otherwise asymptomatic. The CBC, sedimentation rate and C-reactive protein were all normal.

Physical examination demonstrated a well-healed surgical scar with no erythema, drainage or evidence of infection. Both active and passive ranges of motion were decreased. There was palpable crepitus on range of motion. Rotator cuff strength was intact, as was neurologic function of the affected extremity. Radiographs demonstrated a thinned glenoid component with surrounding osteolysis, appearing grossly loose. The humeral component was well positioned with surrounding osteolysis of the medial and lateral proximal humeral bone. There were no radiolucencies around the distal stem and the prosthesis did not appear grossly loose.

                           

















The patient was advised to have a revision shoulder arthroplasty to manage his symptoms and loose glenoid component. Because of the high index of suspicion of an infection, the plan included a one-stage revision to hemiarthroplasty followed by a course of intravenous antibiotic therapy until culture results were finalized. At the time of revision surgery, perioperative antibiotics were held until tissue cultures were obtained. There was abundant scar tissue surrounding the shoulder. A synovial fluid aspiration prior to capsulotomy showed grossly cloudy fluid with a negative gram stain, with no polymorphonuclear cells or organisms seen.  










There was diffuse membranous tissue around both the humeral and glenoid components.  There was osteolysis of the proximal humerus, but the humeral component was securely fixed ; it was removed without complication.  The glenoid component was grossly loose and easily removed.  There was significant wear of the glenoid polyethylene and osteolysis of the underlying glenoid bone.  The rotator cuff was intact.
 A total of 8 samples for culture were taken from various locations within the glenohumeral joint, including the glenoid membrane, collar membrane between the modular humeral head and stem, humeral canal membrane, bursa, glenoid explant, and stem explant.  Due to preoperative and intraoperative concerns of infection, including cloudy fluid, abundant membrane, glenoid loosening and osteolysis, the patient was treated with a one-stage revision consisting of removal of the loose glenoid and single stage exchange of the humeral component using Vancomycin soaked cancellous allograft to secure the stem by impaction grafting.  The remaining glenoid bone was smoothed, no bone graft was added, and no glenoid component was reimplanted.  Cultures were grown on four types of media: blood agar, chocolate agar, Brucella agar and brain-heart infusion broth as previously published. Postoperatively the patient was placed on IV Ceftriaxone 2g daily and Vancomycin 1g daily via PICC line.  The Vancomycin was discontinued after 2 days when the cultures failed to grow MecA CoNS.  All cultures were negative at 21 days at which time all antibiotics were discontinued.  Permanent pathology of the deep tissues identified fibrotic tissue with chronic inflammation, the absence of neutrophils, and a foreign body giant cell reaction consistent with detritic synovitis

After surgery, he was placed on the standard post arthroplasty rehabilitation program focusing on range of motion in the first six weeks, followed by progressive anterior deltoid strengthening. At his six-month follow up visit, the patient was recovering well with no complaints of pain. His Simple Shoulder Test had improved from 5 out of 12 prior to his revision to 10 of 12, and radiographs showed a well-fixed humeral component.

   

How you can support research in shoulder surgery Click on this link.

Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The total shoulder arthroplasty (see this link).
The ream and run technique is shown in this link.
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
Shoulder rehabilitation exercises (see this link).
Follow on twitter: Frederick Matsen (@shoulderarth)


Friday, July 30, 2021

Shoulder arthroplasty - what factors affect its value?

Variation in the value of total shoulder arthroplasty


Using patient-reported outcomes (2 year ASES scores) integrated with time-driven activity-based costing, these authors explored patient-level variation in the value of anatomic and reverse total shoulder arthroplasty (TSA) and characterized factors that contribute to this variation.


They identified 239 patients undergoing elective primary TSA (anatomic or reverse) by an individual surgeon with minimum 2-year follow-up. They calculated "value" as 2-year postoperative American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores divided by hospitalization time-driven activity-based costs. 


After multiplication by a constant, the value of shoulder arthroplasty ranged from 100 to 680.


Factors associated with decreased value were

(1) reverse shoulder arthroplasty  (79-point decrease vs. anatomic arthroplasty)), 

(2) prior ipsilateral shoulder surgery (38-point decrease), 

(3) more self-reported allergies (4-point decrease per 1-unit increase), 

(4) diabetes (33-point decrease), and 

(5) lower preoperative ASES score (0.7-point increase per 1-unit increase).




Comment: Value is commonly defined as the benefit divided by the cost. It is, therefore, considering the numerator and denominator of this quotient.


The numberator=the benefit

Should the numerator be the final patient reported score or the improvement in the score from preoperative to two years after surgery? 


It is likely that a higher preoperative score would be associated with a higher postoperative score (better in => better out), as was found in this study. 


Alternatively, if the numerator of the value equation is the improvement in the score, a lower preoperative score is likely to be associated with greater value (worse in => more opportunity for improvement). 


The Denominator=the cost

These authors used the time-driven activity-based costing (TDABC) methodology to derive inpatient surgical costs for each patient. In their analysis, procedure type (the more costly reverse vs the less costly anatomic arthroplasty) was the main driver of the variation in value. This is especially relevant now because surgeons are increasingly using reverse total shoulders for indications -  such as osteoarthritis with an intact cuff - which are well treated with an anatomic total shoulder. 


It is worthy to note that decreased value was associated with

(1) a history of prior ipsilateral nonarthroplasty shoulder surgery. This could be because of a lower 2 year outcome score or possibly because of increased operating room time and supplies necessary for the management of the altered surgical field.

(2) diabetes; the authors suggest that patients with diabetes experience prolonged and more complicated hospitalizations and worse functional outcomes

(3) a greater number of self-reported allergies; the authors suggest that patients with self-reported allergies experience longer hospital stays and severe pain


Finally, it is important to recognize that the full cost of an arthroplasty includes the costs of of preoperative evaluation (imaging, 3D-planning) and postoperative complications and revisions which may occur years after the procedure. 


How you can support research in shoulder surgery Click on this link.

Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The total shoulder arthroplasty (see this link).
The ream and run technique is shown in this link.
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
Shoulder rehabilitation exercises (see this link).
Follow on twitter: Frederick Matsen (@shoulderarth)




Thursday, July 29, 2021

Total shoulder outcomes: are they related to obesity?

The association of elevated body mass index (BMI) with complications and outcomes

following anatomic total shoulder arthroplasty: a systematic review


These authors conducted a systematic review is to summarize the correlation between elevated body mass index (BMI) and the prevalence of perioperative complications and clinical outcomes following anatomic total shoulder arthroplasty (aTSA).

11 studies were included - 9 studies reported solely on perioperative complications, 1 study solely on functional outcomes, and 1 study on bothbcomplications and outcomes following aTSA.


Most studies were found to have low methodological quality. 


The authors found no significant  association between elevated BMI and overall perioperative medical and surgical complications, surgical site infection (SSI), re-operation without revision, aseptic revision, periprosthetic fracture, intraoperative blood loss, need for blood transfusion, 90-day readmission, absolute hospital LOS or short-term mortality. 


They did find an increased risk for overall revision following aTSA and need for extended hospital LOS in patients with elevated BMI.


Comment: This analysis was compromised by the low quality of the studies evaluated. One of the challenges in trying to relate BMI to surgical outcomes is that the relationship may well be bimodal: individuals with low BMI may be malnourished with its associated risks for fracture and infection while individuals with hi BMI may be at increased risk for falls and extended hospital stay.


Here's another article on the topic:


Effects of Obesity on Clinical and Functional Outcomes Following Anatomic and Reverse Total Shoulder Arthroplasty


These authors identified 1520 patients having primary anatomic (aTSA) arthroplasty and 2054 patients having primary reverse total shoulder arthroplasty with a minimum follow-up of 2 years (mean 5 years). All patients received the same platform shoulder prosthesis. 


Patients were stratified according implant type (anatomic or reverse), and further stratification was based on patient BMI, with obese patients having a BMI ≥ 30 kg/m2 and non-obese patients with a BMI <30 kg/m2


41% of aTSA and 35% of rTSA were obese. 


Obese patients in both groups reported higher preoperative and postoperative visual analog scale (VAS) pain scores (i.e. more pain) and less preoperative and postoperative ROM compared to non-obese patients. 



Compared to non-obese patients, obese patients receiving an aTSA reported significantly worse postoperative SST, Constant, ASES, UCLA, and SPADI scores compared to non-obese patients, and those receiving rTSA reported significantly worse ASES and SPADI scores. However, these

22 differences did not exceed the minimal clinical important difference (MCID) or substantial  benefit (SCB) criteria. 






Statistically significant  differences between obese and non-obese groups were not found to be clinically relevant given  that the differences between the two groups with regards to VAS pain scores, ROM, and functional outcome scores did not exceed the MCID and SCB criteria in both the aTSA and rTSA groups.


Radiographic analysis 23 showed that in rTSA, obese patients had significantly less postoperative scapular notching and a lower scapular notching grade when compared to non-obese patients (P<0.05).


Obese patients had more comorbidities, greater intraoperative blood loss.


Overall complication rates were similar between obese and non-obese groups for both aTSA (7.6% vs. 8.4%; p = 0.57) and rTSA (3.4% vs. 3.9%), including rotator cuff tears, instability, infection, component loosening or failure, dislocation, liner dissociation, stress fracture, neurological complaints, and pain. Revision rates secondary to these complications were also similar between obese and non-obese groups for both aTSA (5.1% vs  5.9%) and rTSA (2.1% vs. 1.7%).


One of the more interesting findings in this study was that obesity seemed to protect patients against scapular notching and a higher notching grade. It seems possible that obesity limited adduction of the arm, reducing the contact between the medial edge of the humeral cup and the lateral scapular neck.


It is of interest to review some of the previous posts on the topic:


Is it safe to operate on patients with obesity?








How you can support research in shoulder surgery Click on this link.

Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The total shoulder arthroplasty (see this link).
The ream and run technique is shown in this link.
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
Shoulder rehabilitation exercises (see this link).
Follow on twitter: Frederick Matsen (@shoulderarth)




Periprosthetic infections of the shoulder

Comparison Study of Patient Demographics and Patient-Related Risk Factors for Peri-Prosthetic Joint Infections Following Primary Total Shoulder Arthroplasty

These authors used the Humana administrative claims database (Pearldiver Platform) to identify patients having primary total shoulder arthroplasty (TSA)(CPT code 23472 (total arthroplasty of glenohumeral joint with glenoid and proximal humeral replacement))


Their study group consisted of patients who were coded as having periprosthetic infection (PJI) within 2-years after the index procedure (ICD-9 diagnosis code 996.66 (infection and inflammatory reaction due to internal joint prosthesis). Patients without this ICD-9 code served as the comparison cohort. 


The query yielded 15,396 patients who underwent primary TSA for glenohumeral OA, of which 191 patients were coded as having PJIs and 15,205 were not. The criteria for the code of PJI were not described nor were the organisms responsible for the code of PJI.


Risk factors associated with a code for PJIs following primary TSA included: pathologic weight loss (OR: 2.06), obesity (BMI 30-40 kg/m sq) (OR: 1.56), male sex (OR: 1.52), and peripheral vascular disease (OR: 1.46). The criteria for pathologic weight loss or severity of peripheral vascular disease were not described.


Comment: This study highlights the limitations of using a claims database in which diagnostic criteria are undefined, allowing each person entering the codes to exercise their own opinion. This limitation is particularly problematic for periprosthetic infections of the shoulder: most of these infections are due to Cutibacterium which requires specific culturing protocols to identify them.


Using the data as presented, the table below was constructed:




The incidence of patients being coded as having PJI was highest for those in the youngest age group (55-59), for males, for those with pathologic weight loss and those with peripheral vascular disease.



How you can support research in shoulder surgery Click on this link.

Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The total shoulder arthroplasty (see this link).
The ream and run technique is shown in this link.
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
Shoulder rehabilitation exercises (see this link).
Follow on twitter: Frederick Matsen (@shoulderarth)







Sunday, July 25, 2021

Managing the stiff (frozen) shoulder

Effects of comorbidities on the outcomes of manipulation under anesthesia for primary stiff shoulder

These authors sought to assess how comorbidities influence the recovery speed and clinical outcomes after manipulation under anesthesia (MUA) in 281 primary stiff shoulders. They divided patients into the control (n . 203), diabetes mellitus (DM)(n . 32), hyperlipidemia (n . 26), and thyroid disorder (n . 20) groups. The mean HbA1c (normal range: 4.5%-5.6%) of the DM group was 7.3%.  Among the 32 diabetic patients, 24 (75%) had HbA1c ≥ 6.5%. 


MUA was considered if all four criteria were met:

(1) limited passive ROM compared with the opposite normal shoulder (passive glenohumeral motion is 20 or less of forward flexion with holding down the scapula by the surgeon, and movements are made mainly using the scapulothoracic motion); 

(2) pain and stiffness persisted for at least 3 months and did not respond to sufficient conservative treatment;

(3) stiff shoulder is in the frozen stage; and 

(4) normal shoulder x-rays.


MUA was performed as an outpatient procedure under interscalene regional anesthesia with the patient in the supine position. With one hand stabilizing the scapula, the range of glenohumeral movement was assessed and recorded. To avoid iatrogenic injuries such as humeral fracture, the surgeon performed manipulation by holding the patient’s arm between the shoulder and elbow with the other hand to form a short lever arm. The shoulder was manipulated sequentially through a range of forward flexion, abduction, external rotation, cross-body adduction, and internal rotation. The procedure was followed by immediate physical therapy.


A successful MUA was defined as achieving the ROM for the passive forward flexion and external rotation at the side within 15 degrees and internal rotation to the posterior within 3 spinal levels compared with the normal contralateral side.


Significant improvements in range of motion (ROM) and clinical scores at 3 months after MUA were observed in all groups. 


Significant differences in ROM among the 4 groups were also observed during follow-up. The DM group had significantly lower ROM values, even at 3 months after MUA, compared with the control group.  The ROM recovery speed after MUA was slowest in the DM group, followed by the thyroid disorder, hyperlipidemia, and control groups.



Most (90.6%) of the DM group experienced late recovery. The proportion of nonsuccessful MUA was higher in the DM and thyroid disorder groups than that in the control and hyperlipidemia groups.




One case of spiral humeral fracture occurred after MUA while rotating the arm externally during this study. No other complications occurred. 


During follow-up, there were no statistically significant differences among groups regarding the visual analog scale, University of California at Los Angeles shoulder, and Constant scores.



Comment: We have found manipulation under anesthesia to be useful for refractory shoulder stiffness in patients without glenohumeral arthritis or osteopenia. We use a short (5 minute) general anesthetic coupled with complete muscle paralysis achieved with succinylcholine.  This has been a safe and effective procedure for patients with refractory idiopathic frozen shoulder and for shoulders with refractory post operative stiffness.

In the photo below, one anesthesiologist (upper left) is providing oxygen ventilation while another (upper right) is administering the intravenous succinylcholine. To avoid the risk of humeral fracture (such as the one reported in this paper) or cuff injury, we manipulate in flexion, cross body adduction, and abduction, but not in rotation.



How you can support research in shoulder surgery Click on this link.

Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The total shoulder arthroplasty (see this link).
The ream and run technique is shown in this link.
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
Shoulder rehabilitation exercises (see this link).
Follow on twitter: Frederick Matsen (@shoulderarth)