**4.1 Patient factors**

1. *Age*: there are no strict age limitations. This technique is ideally suited for younger patients whose age and activity level predict glenoid failure relative to their average life expectancy. For patients older than 65 years, standard total shoulder arthroplasty is more likely to yield a predictable good to excellent result and is the preferred operation unless patients specifically request to forgo glenoid resurfacing after discussion of the options. For the occasional older patient in this category who remains physically very active and engaged in "at risk" activities, non-prosthetic glenoid arthroplasty may be an option if other criteria are met.


586 Recent Advances in Arthroplasty

Fig. 6. Anatomical prosthetic reconstruction of the proximal humerus should seeks to restore the center of rotation relative to the axis of the humeral shaft and the transition between the superior articular surface of the head with the insertion of the articular side of the rotator

In the absence of a scientific method to register the humeral reconstruction with the slippage point on the reamed glenoid, the shoulder arthroplasty surgeon must resort to preoperative planning, intraoperative observation, precise surgical technique and perhaps a bit of good fortune. While the reamed glenoid bone is not as compliant as articular cartilage, it does have the capacity to adapt and remodel according to its mechanical environment and thus, over time there may be some forgiveness to a small margin of error through a process of

Proper patient selection is critical to achieving desired results after this procedure. Selection is based both on anatomical and physiological considerations as well emotional and social aspects of the patient. Foremost, patients with inflammatory arthritis are not candidates for this technique as the absence of a prosthetic glenoid will result in continued glenoid erosion following humeral hemiarthroplasty. Female patients also tend to have less predictable results. This likely relates to having lower bone density and its effect on the potential for continued glenoid pain after reaming and humeral resurfacing. For male patients with osteoarthritis, the

1. *Age*: there are no strict age limitations. This technique is ideally suited for younger patients whose age and activity level predict glenoid failure relative to their average life expectancy. For patients older than 65 years, standard total shoulder arthroplasty is more likely to yield a predictable good to excellent result and is the preferred operation

following selection criteria must be carefully considered for optimal results:

cuff on the greater tuberosity

bedding-in wear.

**4. Indications** 

**4.1 Patient factors** 


Humeral Hemiarthroplasty with Spherical Glenoid

**5. Necessary equipment** 

Reaming: Theory and Technique of The Ream and Run Procedure 589

In order to restore proper load bearing mechanics at the glenohumeral articulation, the reamed glenoid must be sufficiently concave to ensure stability, and sufficiently conforming to avoid load concentration over a small area. Thus, custom-made reamers are necessary so that there is a corresponding reamer for each humeral head diameter.(Figure 7) In order to avoid too much constraint and permit physiological glenohumeral translations, a 2mm mismatch between head diameter and reamer diameter has become the convention, as previously discussed. Thus, if the chosen head size is 52mm, a custom reamer with a diameter of curvature of 54mm is used for glenoid reaming. These reamers should enlarge in circumference as their diameter enlarges in order to contact the surface area of the native glenoid. Cannulated reamers are preferable in that they can follow a pre-drilled K-wire oriented along the glenoid centerline. This greatly improves the accuracy of the reaming process when correction is needed. An open blade reamer design is also beneficial since it allows the surgeon to see the area of bone that has been reamed during version correction.

Fig. 7. Custom reamers are necessary for the Ream and Run. They should have incremental increases in the diameter of curvature by 2mm and should increase in size to cover a larger area of the glenoid face as the diameter increases. Open blade reamers are helpful in

An arthroplasty system of the surgeon's choice can be used with the stipulation that the chosen system allows reliable and reproducible anatomical reconstruction of proximal humeral anatomy. The author currently uses the Synthes EPOCA shoulder system (Synthes,

following the degree of correction during the reaming process.

humeral convexity, center of rotation and soft-tissue balance.

alternative if surgeons are capable of achieving adequate glenoid exposure without humeral head osteotomy. If sequelae of prior trauma have resulted in alteration of the normal proximal humeral anatomy, specifically the head-tuberosity relationship, the surgeon must understand through appropriate imaging how this may affect the goal of achieving an anatomical reconstruction in terms of the position of the arc of the

5. *Emotional History*: patients with ongoing poorly controlled mental health issues are not optimal candidates for this procedure. If patients have symptoms and disability out of proportion to the clinical scenario, have fibromyalgia or a significant poorly defined myofascial component to their pain or if patients have fallen victim to the disease construct of their condition, they are not likely to fair well with the Ream and Run procedure. The optimal patient has demonstrated a balanced self-management approach to their condition, has continued to remain active and engaged despite their physical limitation, and has demonstrated the emotional capacity to deal with the pain and life-altering nature of their diagnosis. Self-assessment scores can sometimes provide a useful window on a patient's emotional state. For instance, those patients who circle "No" on all 12 questions of the Simple Shoulder Score have a self-perceived disability that likely supersedes their actual physical limitation and their outcome after the Ream and Run will be uncertain. If a patient enters a "12" on a 0-10 Visual Analog Pain Scale, one should be concerned about the potential success of the Ream and Run.

### **4.2 Anatomy factors**


alternative if surgeons are capable of achieving adequate glenoid exposure without humeral head osteotomy. If sequelae of prior trauma have resulted in alteration of the normal proximal humeral anatomy, specifically the head-tuberosity relationship, the surgeon must understand through appropriate imaging how this may affect the goal of achieving an anatomical reconstruction in terms of the position of the arc of the humeral convexity, center of rotation and soft-tissue balance.
