**10. Possible reasons why proprioception deteriorates after shoulder arthroplasty**

In shoulder arthroplasty, the operative approach for implantation of a TSA and hemiarthroplasty includes the cutting (and subsequent repair) of the subscapularis muscle and usually release of all glenohumeral ligaments. In cuff tear arthropathy the subscapularis is damaged from the beginning or released during surgery in our technique. However, these structures contain afferent and efferent structures important for proprioception. Therefore, concerning the influence on proprioceptive structures, the surgical procedures for shoulder instability and shoulder replacement are distinct. Since the approach in TSA and hemiarthroplasty is identical, a comparison seems to be valid. The different approach and the lack of the rotator cuff in cuff tear arthropathy limits a direct comparison with the other groups. However, the aim of this study was not the comparison of different types of implants that were implanted for different indications. The aim of this study was to assess proprioception changes three years after shoulder arthroplasty within the three groups. What we observed in our study is that nociceptors may also play an important role. During the repeat postoperative measurement, the patients mentioned that they were lacking the information input of pain sensation that they had usually during motion of the arm before

Development of Proprioception After Shoulder Arthroplasty 613

pain free increase of range of motion in activities of daily living, as we described in a

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

Research fund of the Department of Orthopaedic and Trauma Surgery of the Hospital of the

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

We thank the research fund of the Department of Orthopaedic and Trauma Surgery of the Hospital of the University of Heidelberg for the financial support of the study. Furthermore, we would like to thank the motion analysis team of the University of Heidelberg, especially Petra Armbrust and Waltraud Schuster, for the practical support during the study.[Level of

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[5] Constant, C.R. and A.H. Murley, *A clinical method of functional assessment of the shoulder.*

[6] Cuomo, F., M.G. Birdzell, and J.D. Zuckerman, *The effect of degenerative arthritis and* 

[7] Deshmukh, A.V., et al., *Total shoulder arthroplasty: long-term survivorship, functional outcome, and quality of life*. J Shoulder Elbow Surg, 2005. 14(5): p. 471-9. [8] Doorenbosch, C.A., J. Harlaar, and D.H. Veeger, *The globe system: an unambiguous* 

[9] Gamage, S.S. and J. Lasenby, *New least squares solutions for estimating the average centre of* 

*rotation and the axis of rotation*. J Biomech, 2002. 35(1): p. 87-93.

*prosthetic arthroplasty on shoulder proprioception.* J Shoulder Elbow Surg, 2005. 14(4):

*description of shoulder positions in daily life movements.* J Rehabil Res Dev, 2003. 40(2):

previous study [13], is the main improvement for the patient after surgery.

Shoulder proprioception deteriorates after shoulder arthroplasty.

Evidence : Level III, Case-Control Study, Treatment Study.

*errors*. Gait Posture, 2005. 21(2): p. 197-211.

Clin Orthop Relat Res., 1987(214): p. 160-164.

**Summary sentence** 

**Source of funding** 

University of Heidelberg.

**12. Aknowledgements** 

**13. References** 

p. 345-348.

p. 147-55.

entity related to the subject of this article.

**Disclosures** 

the study.

surgery. The lacking of this afferent input might adversely influence the postoperative proprioception performance with the AAR.
