These authors evaluated the clinical and radiological outcome of an anatomical short-stem shoulder prosthesis to treat primary osteoarthritis of the glenohumeral joint in 66 patients (67 shoulders) with a mean age of 76 years (63 to 92) at two different timepoints (T1, mean 2.6±0.5 years; T2, mean 5.3±0.7 years).
The zones around the humeral stem were analyzed for three features of bone remodelling: condensation lines, cortical bone narrowing and osteopenia (CNO), and spot welds.
No stem loosening was seen. High bone adaptation was present in 42% of shoulders at T1, with a slight decrease to 37% at T2. Cortical bone narrowing and osteopenia in the region of the calcar decreased from 76% to 66% between T1 and T2.
Patients with high bone adaptation had a significantly higher mean filling ratio of the stem at the metaphysis (0.60±0.05, vs 0.55±0.06; p = 0.003) and at the diaphysis (0.65± 0.05 vs 0.60± 0.05; p = 0.007).
Cortical contact of the stem was also associated with high bone adaptation (14/25 shoulders, p = 0.001). The clinical outcome was not influenced by the radiological changes.
The authors concluded that shoulder arthroplasty using a short-stem humeral component resulted in good clinical outcomes with no evidence of loosening. However, approximately 40% of the shoulders developed substantial bone loss in the proximal humerus at between four and seven years of follow-up.
The authors concluded that shoulder arthroplasty using a short-stem humeral component resulted in good clinical outcomes with no evidence of loosening. However, approximately 40% of the shoulders developed substantial bone loss in the proximal humerus at between four and seven years of follow-up.
Comment: As pointed out in another recent article (see this link), thicker short stems provide better fixation but risk stress shielding in comparison to thinner short stems.
The authors of the study on short stemmed humeral components with mid term followup state "Total shoulder arthroplasty using a standard-length humeral stem is still the benchmark procedure. It has a low prevalence of clinical loosening and long-term complications." They go on to state that standard long-stem humeral components can be associated with complications such as intraoperative fracture of the humerus, stress shielding, aseptic loosening, and periprosthetic fracture.
The authors of the study on short stemmed humeral components with mid term followup state "Total shoulder arthroplasty using a standard-length humeral stem is still the benchmark procedure. It has a low prevalence of clinical loosening and long-term complications." They go on to state that standard long-stem humeral components can be associated with complications such as intraoperative fracture of the humerus, stress shielding, aseptic loosening, and periprosthetic fracture.
We have found that impaction grafting of standard length smooth humeral stems with low filling ratios can effectively avoid these complications as pointed out in this post:
Radiographic outcomes of impaction-grafted standard-length humeral components in total shoulder and ream-and-run arthroplasty: is stress shielding an issue?
These authors evaluated humeral stress shielding after shoulder arthroplasty performed with a smooth, standard-length humeral stem fixed with impaction autografting.
The overall radiographic results are shown below
The 48 ream-and-run procedures showed partial calcar osteolysis in 9 cases (19%) and the 78 TSAs showed partial calcar osteolysis in 19 cases (24%) and complete calcar osteolysis in 2 (3%).
The Simple Shoulder Test score improved from 3.9±2.5 to 9.9±2.4.
Humeral component subsidence or component shift was observed in 3 ream-and-run procedures (6%) and in 8 TSAs (10%). These radiographic findings were not significantly associated with patient demographic characteristics, canal-filling ratios, or clinical outcomes.
The authors concluded that this independent assessment of the 2-year radiographic and clinical outcomes of a conventional smooth humeral stem inserted with impaction autografting demonstrates the clinical utility of this bone-preserving approach to humeral component fixation with minimal complications; good clinical outcomes; and low rates of bone loss, component subsidence, and shift in position.
A video of our approach to total shoulder arthroplasty can be seen by clicking this link.
These authors evaluated humeral stress shielding after shoulder arthroplasty performed with a smooth, standard-length humeral stem fixed with impaction autografting.
Prior to placement of the final component, cancellous autograft harvested from the humeral head was placed in the humeral canal and pressed into place using a humeral impactor with the same stem geometry as the implant. Autograft was progressively inserted until the impactor fit tightly within the humerus. The final uncoated, smooth, stemmed, fixed-angle humeral component with the desired head geometry was then driven into the prepared canal.
At two years after surgery, the radiographic appearances were evaluated by an independent experienced shoulder surgeon from another institution not involved in the care of these patients. The metaphysical and diaphysial filling ratios were measured as shown below.
The filling ratios were small, showing a substantial preservation of bone stock.
The Simple Shoulder Test score improved from 3.9±2.5 to 9.9±2.4.
Humeral component subsidence or component shift was observed in 3 ream-and-run procedures (6%) and in 8 TSAs (10%). These radiographic findings were not significantly associated with patient demographic characteristics, canal-filling ratios, or clinical outcomes.
The authors concluded that this independent assessment of the 2-year radiographic and clinical outcomes of a conventional smooth humeral stem inserted with impaction autografting demonstrates the clinical utility of this bone-preserving approach to humeral component fixation with minimal complications; good clinical outcomes; and low rates of bone loss, component subsidence, and shift in position.
After three decades of use, impaction autografting of a smooth standard-length stem remains our preferred method for bone-preserving humeral component fixation.
Impaction allografting remains our preferred method for addressing failed prior humeral component fixation.
A video of our approach to total shoulder arthroplasty can be seen by clicking this link.
=====
We have a new set of shoulder youtubes about the shoulder, check them out at this link.
Be sure to visit "Ream and Run - the state of the art" regarding this radically conservative approach to shoulder arthritis at this link and 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 arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'
