**11. What can we do to avoid postoperative deterioration of proprioception?**

Another issue is how we could diminish the loss of proprioception after shoulder replacement. Certainly we have to take a look at the surgical procedure. In the cases of TSA and HEP the deltopectoral approach was used with detachment of the subscapularis tendon and release of all glenohumeral ligaments. In shoulder replacement different procedures exist for detachment of the subscapularis tendon. If the external rotation is > 20°, according to our concept the subscapularis tendon is divided 5-10 mm medial to its insertion at the lesser tuberosity. The lateral tendon stump will permit an end-to-end suture at the end of surgery. If the external rotation is <20°, the detachment of the subscapularis tendon from the lesser tuberosity is recommended, because this allows to gain length by medializing the tendon insertion after implantation of the prosthesis. At the end of the surgery, the subscapularis tendon is repaired in slight abduction and external rotation of the arm either with an end-to-end suture or, in the presence of joint contracture, reattached with the help of previously mounted transosseous sutures [10, 24]. This refixation is important, because otherwise it carries the risk of a later anterior instability of the prosthesis and loss of shoulder function.

This intraoperative soft tissue management could play an important role for the proprioceptive outcome according to a recently published study by Rokito et al. [25]. They investigated the degree to which surgical approach affects recovery of strength and proprioception. The recovery of strength and proprioception after open surgery for recurrent anterior glenohumeral instability was compared for two surgical procedures. Group 1 underwent an open inferior capsular shift with detachment of the subscapularis, and group 2 underwent an anterior capsulolabral reconstruction without detachment of the subscapularis. In group 1 the subscapularis was split horizontally at the junction of its upper two-third and lower one-third, and a glenoid-sided capsular shift was performed, followed by reapproximation of the split. At 6 months after surgery in group 1 patients there were still significant deficits in mean position sense and strength values. Rokito concluded that detachment of the subscapularis delays recovery of strength and proprioception. These findings can explain the deterioration of proprioceptive outcome in shoulder arthroplasty which usually implies the detachment of the subscapularis muscle. Another important issue is the release of the glenohumeral ligaments that play an important role in proprioception of the shoulder. Postoperative management with immobilizing in a Gilchrist sling or an abduction pillow, physiotherapy management including a temporary avoidance for rotational movements to allow for healing of the subscapularis muscle as well as proprioceptive neuromuscular facilitation exercises might play an important role for the individual proprioceptive outcome.

Performing shoulder arthroplasty did negatively affect one component of shoulder proprioception that was measured by the active angle-reproduction test. This might be related to the surgical approach that includes divison of the subscapularis muscle and the glenohumeral ligaments. In order to be able to diminish negative influences on postoperative proprioception further prospective studies will have to evaluate pre- and intraoperative variables to improve proprioception after shoulder replacement. Although proprioception does not improve three years after implantation of shoulder arthroplasty, a pain free increase of range of motion in activities of daily living, as we described in a previous study [13], is the main improvement for the patient after surgery.

### **Summary sentence**

Shoulder proprioception deteriorates after shoulder arthroplasty.

### **Disclosures**

612 Recent Advances in Arthroplasty

surgery. The lacking of this afferent input might adversely influence the postoperative

**11. What can we do to avoid postoperative deterioration of proprioception?**  Another issue is how we could diminish the loss of proprioception after shoulder replacement. Certainly we have to take a look at the surgical procedure. In the cases of TSA and HEP the deltopectoral approach was used with detachment of the subscapularis tendon and release of all glenohumeral ligaments. In shoulder replacement different procedures exist for detachment of the subscapularis tendon. If the external rotation is > 20°, according to our concept the subscapularis tendon is divided 5-10 mm medial to its insertion at the lesser tuberosity. The lateral tendon stump will permit an end-to-end suture at the end of surgery. If the external rotation is <20°, the detachment of the subscapularis tendon from the lesser tuberosity is recommended, because this allows to gain length by medializing the tendon insertion after implantation of the prosthesis. At the end of the surgery, the subscapularis tendon is repaired in slight abduction and external rotation of the arm either with an end-to-end suture or, in the presence of joint contracture, reattached with the help of previously mounted transosseous sutures [10, 24]. This refixation is important, because otherwise it carries the risk of a later anterior instability of the prosthesis and loss of

This intraoperative soft tissue management could play an important role for the proprioceptive outcome according to a recently published study by Rokito et al. [25]. They investigated the degree to which surgical approach affects recovery of strength and proprioception. The recovery of strength and proprioception after open surgery for recurrent anterior glenohumeral instability was compared for two surgical procedures. Group 1 underwent an open inferior capsular shift with detachment of the subscapularis, and group 2 underwent an anterior capsulolabral reconstruction without detachment of the subscapularis. In group 1 the subscapularis was split horizontally at the junction of its upper two-third and lower one-third, and a glenoid-sided capsular shift was performed, followed by reapproximation of the split. At 6 months after surgery in group 1 patients there were still significant deficits in mean position sense and strength values. Rokito concluded that detachment of the subscapularis delays recovery of strength and proprioception. These findings can explain the deterioration of proprioceptive outcome in shoulder arthroplasty which usually implies the detachment of the subscapularis muscle. Another important issue is the release of the glenohumeral ligaments that play an important role in proprioception of the shoulder. Postoperative management with immobilizing in a Gilchrist sling or an abduction pillow, physiotherapy management including a temporary avoidance for rotational movements to allow for healing of the subscapularis muscle as well as proprioceptive neuromuscular facilitation exercises might play an important role for the

Performing shoulder arthroplasty did negatively affect one component of shoulder proprioception that was measured by the active angle-reproduction test. This might be related to the surgical approach that includes divison of the subscapularis muscle and the glenohumeral ligaments. In order to be able to diminish negative influences on postoperative proprioception further prospective studies will have to evaluate pre- and intraoperative variables to improve proprioception after shoulder replacement. Although proprioception does not improve three years after implantation of shoulder arthroplasty, a

proprioception performance with the AAR.

shoulder function.

individual proprioceptive outcome.

All authors, their immediate family, and any research foundation with which they are affiliated did not receive any financial payments or other benefits from any commercial entity related to the subject of this article.

### **Source of funding**

Research fund of the Department of Orthopaedic and Trauma Surgery of the Hospital of the University of Heidelberg.

The local ethics committee approved the study (S-305/2007) and all patients consented to the study.
