Hemiarthroplasty rather than total shoulder for glenohumeral arthritis: results with a pyrocarbon humeral head.

There is a surge of interest in the use of humeral hemiarthroplasty - rather than conventional total shoulder -  in the management of patients with glenohumeral arthritis. Many such procedures have been performed using a cobalt-chrome humeral head in the ream and run. Now there is growing use of Pyrocabon humeral heads with the idea that glenoid wear/humeral medialization could be lessened because of the special lubricating properties of their articular surface. 

Last month's post The Ream and Run - how much of an issue is glenoid wear? pyrocarbon vs. chrome cobalt? summarized some of the relevant data. 

This week a new study was published: Five-Year Radiographic and Clinical Outcomes of Pyrocarbon Hemiarthroplasty for Glenohumeral Arthritis and Osteonecrosis, which evaluated the progression of humeral head medialization in patients having pyrocarbon hemiarthroplasty. This was a methodologically strong study; it was a prospective FDA, IDE investigation. Standardized protocols were used from the start with predefined outcome measures. The inclusion rate was high: 45 of 54 potentially eligible patients. Rigorous imaging standards were imposed from the start and consistent across all time points. The radiographic analysis was blinded and used standardized software. The correlation analysis was formalized. Kaplan-Meier curves were carried out with 7 year survival rates. Radiographic measurements and patient reported outcomes were documented at three time points. 

Included patients had a mean age of 52 years and a mean follow-up of 73 months. In addition to the pyrocarbon humeral hemiarthroplasty, 60% had a glenoidplasty, 27% had glenoid drilling only, 9% had no glenoid treatment. 

Significant improvements were observed across all outcome measures. Patient satisfaction was 98%. The 7-year revision-free survival rate was 95.7%. Two patients were revised for infection. Posterior subluxation in decentered shoulders decreased from 27% preoperatively to 20% postoperatively. The mean medialization of the humeral head averaged 2.9  mm at the 2-year follow-up (1.5 mm/yr) and after that increased at a lower rate ( 0.3 mm/year) to an average of 4.0 mm at the time of the final follow-up of 6 years for an overall medialization of 0.66 mm/year. 

Interestingly, Pearson correlation analysis found no relationship between medialization and clinical outcomes. Patients with significant glenoid wear achieved the same results as those with minimal wear. Younger age was the only significant predictor of severe medialization (p=0.030), however this increased radiographic wear in younger patients did not correlate with worse clinical outcomes. In fact, none of the measured variables - including medialization, age, sex, glenoid morphology, and treatment type - correlated with clinical outcomes.

The wear in this pyrocarbon study can be compared to that in another 2025 study that used a chrome cobalt humeral head with reaming of the glenoid (the traditional ream and run): Characterizing glenoid wear after hemiarthroplasty with concentric glenoid reaming: a study of 113 arthroplasties at a mean of 6.7 years of follow-up. Both studies had similar age (59 yrs RnR and 52 yrs Pyro) and sex (92% RnR and 78% Pyro) profiles. 

The method of measuring medialization in the Pyro study

was similar to that used in Characterizing Glenoid Wear after Hemiarthroplasty with Concentric Glenoid Reaming: A Study of 113 Arthroplasties at a Mean of 6.7 Years

As seen in the figure below, the wear rates for the traditional ream and run do not appear inferior to those for Pyrocarbon. The traditional ream and run study demonstrated a plateau in wear beyond 6 years based on 11 time points. The trajectory of pyrocarbon wear is less certain in that it is based on 3 time points.

Both studies showed high satisfaction and improvement in clinical outcomes. The RnR study was retrospective with 113 of 408 patients included, 12 had open revision. The Pyro study was prospective with 45 of 54 patients included, 2 had open revision; the difference in revision rate was not statistically significant. Neither study found a relationship between glenoid wear and patient-reported outcomes. Formal correlation analysis (pyrocarbon) and group comparisons (ream-and-run) both showed that patients achieved excellent results (>97% satisfaction, significant functional improvement) regardless of wear amount. None of factors studied were associated with clinical outcome.

Clinical Implications: Humeral hemiarthroplasty - either traditional ream and run or pyrocarbon hemiarthroplasty - are important surgical considerations for young patients with glenohumeral arthritis, especially if they wish to avoid the risks and limitations associated with the polyethylene glenoid component used in total shoulder arthroplasty. Both procedures were associated with over 97% rate of satisfaction. While younger age was associated with increased wear, none of the factors considered in these studies - including glenoid wear - were associated with the clinical outcome.

While it seems that a randomized clinical trial may be useful in comparing these two procedures, there would be some challenges in such a study as pointed out in Is pyrocarbon better than a ream and run? - a randomized controlled trial

Different heads

Pileated woodpecker

White headed woodpecker

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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 ream and run procedure (see this link)
The total shoulder arthroplasty (see this link)
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link)
Shoulder rehabilitation exercises (see this link).

Locked posterior dislocation managed with hemiarthroplasty in a young man with seizures

A young man with seizures incompletely controlled with medications and a brain stimulator, presented with posterior instability of the left shoulder that recurred after multiple closed reductions. His Grashey view showed overlap of the humeral and glenoid articular surfaces.

His scapular Y view showed posterior displacement of the humeral head relative to the glenoid.

His CT showed a locked posterior dislocation

Because of his incompletely controlled seizures a hemiarthroplasty was selected instead of a soft tissue procedure or allograft.

The locked position of the humeral head behind the glenoid was seen after the subscapularis peel.

The defect in the anterior humeral head was seen after reduction of the dislocation.

An anteriorly eccentric humeral component with a diameter of curvature equal to his native head was fixed to a standard impaction grafted humeral stem. 

The day after surgery, he was started on assisted elevation of the arm. There was no evidence of posterior instability.

Self-assisted range of flexion at 6 days post op. 

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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 ream and run procedure (see this link).

The total shoulder arthroplasty (see this link).

The cuff tear arthropathy arthroplasty (see this link).

The reverse total shoulder arthroplasty (see this link).

The smooth and move procedure for irreparable rotator cuff tears (see this link).

Shoulder rehabilitation exercises (see this link).

Stemless humeral head replacement - does it offer increased value to the patient?

 Survival of Stemless Humeral Head Replacement in Anatomic Shoulder Arthroplasty.

These authors reviewed their experience at a mean followup of 126 months with a stemless humeral head component.

The review included 75 patients with a mean age of 57 years at surgery (40 hemi- (HSA), 35 total shoulder arthroplasties (TSA), 38 females, 37 male). 

The patient and shoulder characteristics are shown in the table below,

There was no significant difference in pre- and post-op CS between the hemiarthroplasty group (44.8 pre-op, 67.1 post-op) and the total shoulder group (44.4 pre-op, 68.9). 

They found no evidence of humeral component loosening or stress shielding.

Upward migration of the humeral head was observed in 17.5% (21.6% HSA, 11.5% TSA).

18.3% had a rotator-cuff deficiency at follow-up (HSA: 13.9%, TSA 25%;p=0.280). 

The overall revision rate was 15.1%: 20% for TSA and 7.5% for hemiarthroplasty. 

9.3% of stemless shoulder arthroplasties were revised to a reverse total shoulder arthroplasty (5% of HSA, 14.3% of TSA. 

For the hemiarthroplasties, secondary glenoid wear occurred in 64.3%  but none were converted to TSA. 

For the total shoulders, an incomplete radiolucent line < 2mm was observed in 36.4% and glenoid loosening was found in 11.4% of cemented glenoid components. 

Comment: It is of interest to see the authors' use of hemiarthroplasty in over half of these cases, the issue of upward migration of the humeral head, the glenoid component failure rate in the total shoulder group, the equivalency of the clinical outcomes between total shoulder and hemiarthroplasty, and the higher revision rate for the total shoulder group.

The authors state that "the clinical and radiological long-term results of anatomic shoulder arthroplasty using a stemless humeral head implant have comparable good to the long-term results compared to standard stemmed anatomic shoulder arthroplasty". It is unclear whether the stemless component offers increased value to the patient in comparison to the standard approach to shoulder arthroplasty. 

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359 failed primary shoulder hemiarthroplasties that were surgically revised

Primary Shoulder Hemiarthroplasty: What Can Be Learned From 359 Cases That Were Surgically Revised? 

These authors analyzed the characteristics of patients having surgical revision of a prior primary humeral hemiarthroplasty with the goal of answering three questions

(1) What are the common characteristics of shoulder hemiarthroplasties having a revision? 

(2) What are the common characteristics of the subset of revised shoulder hemiarthroplasties that were performed for fracture? 

(3) What are characteristics of the subset of all revised hemiarthroplasties that were associated with glenoid bone erosion? 

These patients had severe loss of self-assessed shoulder comfort and function, with Simple Shoulder Test (SST) scores averaging 2.2 +/- 2.2 of the maximum score of 12. The average time from index arthroplasty to revision was 3.4 years.

Common characteristics of the revised hemiarthroplasties included 

female sex (81%), 

rotator cuff (89 of 359; 25%) or subscapularis (81 of 359; 23%) failure, 

problems related to prior fracture (154 of 359; 43%), 

glenoid erosion 125 of 359; 35%), and 

component malposition (89 of 359; 25%). 

Hemiarthroplasties performed for fracture-related problems often were associated with tuberosity malunion or nonunion (58 of 79; 73%) and decentering of the humeral component on the glenoid surface (45 of 71; 63%). 

Major erosion of the bony glenoid (Grade 3 or 4) was more common in decentered hemiarthroplasties (42 of 102; 41%) than for centered hemiarthroplasties (36 of 146; 25%) (Fisher's exact p = 0.008) and more common for hemiarthroplasties positioned in valgus (28 of 50; 56%) than for those positioned in neutral or varus (40 of 188; 21%) (Fishers' exact p < 0.0001). 

Based on these findings the authors suggested that some revisions of primary hemiarthroplasties may be avoided by surgical techniques directed at centering the prosthetic humeral articular surface on the glenoid concavity using proper humeral component positioning and soft tissue balance, by avoiding valgus positioning of the humeral component, and by managing glenoid disorders with a primary glenohumeral arthroplasty rather than a hemiarthroplasty alone. When durable security of the subscapularis, rotator cuff, and tuberosities is in question, the surgeon may consider a reverse total shoulder arthroplasty.

Comment: Primary shoulder hemiarthroplasty is a commonly used procedure for the treatment of various shoulder disorders. In the treatment of a proximal humeral fracture, primary hemiarthroplasty is considered when displaced fracture fragments cannot be treated with internal fixation or when there is concern regarding head collapse. In the treatment of shoulder arthritis, capsulorrhaphy arthropathy, or avascular necrosis, a primary hemiarthroplasty may be performed if there is minimal glenoid disease, if the patient is young, if the shoulder is too tight to admit a glenoid component, if there is insufficient bone stock to support a prosthetic glenoid, if there is concern for possible infection, if the patient wishes to avoid the risks and limitations associated with a glenoid component, or if the surgeon is not comfortable with performing another type of shoulder arthroplasty. Each of these indications can be associated with an increased risk of failure and subsequent revision.

This study calls attention to some of the factors that can be associated with a poor outcome and provides some possible approaches for reducing the need for surgical revision of a failed hemiarthroplasty.

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How you can support progress in shoulder surgery

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Management of a posterior locked fracture dislocation

A 55 year old triathlete fell while bike riding, landing on his outstretched left hand. He developed posterior instability that was treated with a posterior arthroscopic stabilization at an outside facility. Subsequently it was noted that he had developed a locked posterior fracture dislocation with both an anterior humeral and a posterior glenoid defect as shown by the images below.

He elected an open reduction and humeral hemiarthroplasty with an anteriorly eccentric humeral head and a posterior glenoid bone graft using part of the resected humeral head. At surgery his shoulder was very stable under vigorous posterior loading.

The postoperative films are shown below

The plan is for external rotation isometrics and 6 weeks immobilization in a neutral rotation brace.
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The reader may also be interested in these posts:

Healing through joint replacement

Supporting progress in shoulder surgery

Consultation for those who live a distance away from Seattle.

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Click here to see the new Rotator Cuff Book

Information about shoulder exercises can be found at this link.

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 run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'

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Propionibacterium in a primary arthroplasty after a Latarjet procdure, seeing what you look for

A man is his early twenties presented with pain and stiffness in the shoulder after two prior instability procedures, the last being a Latarjet in 2012.

He had a primary hemiarthroplasty with removal of the screw, the head of which was rubbing on his humeral head. Because of the global loss of cartilage seen on his preoperative films, we obtained cultures before administering antibiotics.

At surgery there was no obvious evidence of infection. The humeral head showed global loss of cartilage as shown here.

His postoperative films are shown here.

After surgery he was started on the 'yellow' antibiotic protocol. Range of motion exercises were started on day one and he had 150 degrees of motion on discharge two days later.

Five days after surgery, the cultures grew out coagulase negative staph in one specimen and Propionibacterium in three (capsule, humeral head #1 and humeral head #2). At that time a PICC line was plaeced and he was converted to the 'red' antibiotic protocol.

Comment: It would have been easy to miss this infection. Our index of suspicion was heightened by the generalized destruction of the joint surface in contrast to the local destruction that would be expected from contact of the humeral head with the screw.

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Consultation for those who live a distance away from Seattle.

To see the topics covered in this Blog, 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 run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'

See from which cities our patients come.

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Hemiarthroplasty (including hemiarthroplasty with biological resurfacing)

1. Description - a surgical procedure in which the humeral articular surface is replaced without attention to the glenoid side of the joint. A humeral hemiarthroplasty is not the same as a ream and run.

In the hemiathroplasty the rough humeral joint surface (see below)



is replaced with a smooth metal surface (see below).



The humeral head prosthesis is connected to a stem (titanium alloy) the tapered body of which fits inside the humerus.






2. Indications - In glenohumeral arthritis, both sides of the joint are affected so that either a ream and run or a total shoulder arthroplasty is usually used in conjunction with the humeral joint surface replacement. However, in certain circumstances a hemiarthroplasty alone may be considered: (1) the diagnosis is avascular necrosis and the glenoid joint surface is unaffected; (2) diagnosis is dysplasia and there is insufficient glenoid bone stock for a glenoid arthroplasty, (3) the diagnosis is osteoarthritis, but the glenoid is smooth and congruent with the humeral head, (4) the shoulder is so tight that a glenoid component cannot be inserted properly; (5) there is concern about the status of the rotator cuff (a special humeral hemiarthroplasty prosthesis is available for the management of cuff tear arthropathy when pseudo paralysis is not present); (6) there is concern about low grade infection (an uncemented non-ingrowth hemiarthroplasty is safer to revise that a total shoulder arthroplasty).

3. Technique

The important consideration in a humeral hemiarthroplasty is that the diameter of curvature of the prosthetic humeral head needs to match or slightly exceed that of the native humeral head that it replaces. This is because the glenoid shape is not altered by the procedure.

The exposure and the humeral hemiarthroplasty

An important aspect of our technique is fixation of the humeral component without cement, without bony ingrowth, and without weakening the humeral shaft by removing bone from its inner endosteal surface. The fixation must recognize that the endosteal anatomy is variable. The inside of the humerus (arm bone) may be cylindrical or tapered.


The inside of the humerus changes in shape as one moves down the shaft.




Trying to fit a prosthesis by reaming the inside of the bone may substantially weaken it.









Trying to force a tight fit risks fracture.









We find that the safest method for securing the stem within the humeral canal is to use impaction grafting with bone harvested from the arthritic humeral head (which is removed at the time of surgery) to conform the inner surface of the bone to the prosthesis. Some have likened this fitting of the patient's bone the prosthesis to the fitting of the traveler to the bed by the inn keeper Procrustes.









As a result, the tapered stem is securely fixed with a biological press fit that safely distributes the load from the prosthesis to the humerus.



Antibiotics after joint replacement

4. Rehabilitation - The most important aspect of the post operative rehab program is preventing stiffness - using the exercises shown here. Of particular concern is the subscapularis.

Once the range of motion is well established and after 6 weeks, we usually start early strengthening and the traction three.

5. Results - The results of hemiarthroplasty depend on the diagnosis for which the procedure is performed - as mentioned under 'indications', it is often performed in unusual circumstances.  Hemiarthroplasty has been combined with meniscal allograft or with soft tissue interposition ("biological resurfacing"), but the addition of the interposition does not seem to improve the results.

6. Complications - the possible risks of hemiarthroplasty include stiffness, pain, infection, fracture and glenoid wear. If stiffness and pain are persistent at six weeks after surgery, a gentle manipulation under anesthesia with complete muscle relaxation is often helpful. If stiffness is present months after the procedure, a surgical soft tissue release is an option. Infection is uncommon after this procedure, especially if advanced prophylactic antibiotics (Ceftriaxone and Vancomycin) are used before and for a day after surgery. Fractures are extremely rare with the impaction bone grafting technique. Glenoid wear is a particular risk when the quality of the bone is poor or when the glenoid surface is not congruent with the humeral prosthesis.

Some surgeons have attempted to combine the hemiarthroplasty with biological resurfacing of the glenoid. This procedure has fallen into disfavor. 

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Shoulder joint replacement step by step: exposure and the humeral side of the arthroplasty

1. Preparation

   a. Preoperative assessment
         i. The patient should be in the best state of health for this elective procedure.
         ii. Dental hygiene as well as heart, lung, blood pressure, and urinary considerations need to be optimized and stable.
         iii. The skin should be healthy and the axilla and entire upper extremity free of any scratches or other lesions.
         iv. The neurologic status of the arm is documented along with the neck range of motion and the ability of the mouth to open for insertion of the airway.
         v. Informed consent is obtained with explanation of the risk of pain, stiffness, weakness, nerve injury, vascular injury, fracture, loosening, instability, infection, and the need for revision surgery as well as anesthetic complications and death.
   b. In the operating room
         i. Foley catheters are often used for male patients.
         ii. An 18 gauge intravenous catheter is inserted in the contra lateral arm.
         iii. Unless there is a documented allergy to cephalosporin or major reaction to penicillin, prophylactic antibiotics – preferably Ceftriaxone and Vancomycin because of their effectiveness against Propionibacterium and coagulase negative staphylococcus - are administered prior to surgery and continued for 24 hours.
         iv. General anesthesia is preferred to enable postoperative neurological examination and to avoid the potential risks of nerve blocks.
         v. Anticoagulants are only used for patients with major risk factors, such as a prior pulmonary embolism.
         vi. The patient is securely positioned in a comfortable low beach chair position with the glenohumeral joint at the edge of the operating table.
         vii. Sequential leg compression is used during the case to avoid venous pooling.







   c. The approach
         i. The skin of the entire arm and shoulder is doubly prepared with Chlorhexidine.
         ii. The intended skin incision is marked over the deltopectoral interval along a line connecting the mid clavicle to the mid lateral humerus.
         iii. The arm is draped using an adhesive plastic drape to close off the axilla.
         iv. The shoulder is approached through a deltopectoral incision. The clavipectoral fascia is incised up to but not through the coracoacromial ligament.






         v. The subscapularis and anterior capsule are incised from its insertion to the lesser tuberosity with care to preserve the biceps tendon if it is intact. (Alternative techniques include subscapularis tenotomy and lesser tuberosity osteotomy). At the bottom of this post are links to other posts regarding the management of the subscapularis in shoulder arthroplasty.

   d. Humeral preparation
         i. A broad flat Darrach elevator is placed behind the humeral head and used to gently deliver the humeral head anteriorly
         ii. The medullary canal of the humerus is entered from a starting point near the supraspinatus insertion. Successively larger medullary reamers are placed down the canal until the tip of the reamer just engages the endosteal surface of the diaphysis. If the reamer cannot be fully inserted for the length of the prosthetic stem, one size smaller reamer is selected. The diameter of this reamer will be the diameter of the prosthetic stem. Reaming of the endosteal surface of the diaphysis is avoided to prevent causing a stress riser at the tip of the prosthesis that could predispose the humerus to fracture.






         iii. The humeral head is resected at a 45 degree angle with respect to the inserted reamer and in 30 degrees of retroversion. Care is taken to avoid injuring the rotator cuff while the head is being resected.
         iv. The arthritic glenoid is managed by either a ream and run concentric reaming or by the insertion of a glenoid component.
         v. The appropriate head prosthesis (diameter of curvature and height and offset) is selected to optimize mobility and stability. We use the 40/50/60 rule.


   vi. If there is posterior drop back, an eccentric humeral head and or a rotator interval plication may be needed.






         vii. The prosthesis is inserted using impaction bone grafting. This avoids the need for cement or bony ingrowth, each of which can complicate revision should it become necessary. This approach also strengthens the bone and minimizes the risk of periprosthetic fracture.






      viii. Once the humeral component is in place, there are three critical checks. If any of these is a problem, the offending bone can be removed or, if necessary, the prosthesis can be repositioned – this is one of the major advantages of impaction grafting (you can get it wrong and still make it right).

         1. Is there abutment at Pooh Corner?







         2. Is there posterior abutment leading to open booking?



         3. Is the register proper (does the humeral head fit nicely in the glenoid)?


      ix. Once the humeral arthroplasty is complete, the subscapularis is securely repaired to the lesser tuberosity using six sutures

Additional posts relevant to the subscapularis: Protection 1, Protection 2, Protection 3, Surgical management 1, Surgical management 2, Lesser tuberosity osteotomy, Tuberosity osteotomy vs tenotomy 1, Tuberosity osteotomy vs tenotomy 2, Tuberosity osteotomy vs tenotomy 3, Function after transosseous repair

**To see more of the Shoulder Arthritis Book, click here.**