Abstract
Aim: To assess shoulder proprioception before and after a new surgical treatment for multi-directional instability.
Methods: A pilot study assessing shoulder proprioception in asymptomatic controls (n=6), pre-operative patients (n=7) awaiting surgery for multidirectional instability (having failed rehabilitation) and post-operative patients (n=7) having undergone thermo-capsular shrinkage and rehabilitation. Data were obtained using the Proprioception Assessment System developed at our centre following a standardised protocol to record threshold to detection of passive movement (TTDPM) and reproduction of passive position (RPP) in three positions of rotation.
Results: For controls, TTDPM at 0 degrees, +30 degrees and −30 degrees was 1.08 degrees ± 1.05 degrees, 1.75 degrees ± 1.80 degrees and 1.61 degrees ± 1.68 degrees respectively. In the pre-operative group the asymptomatic shoulders had values of 2.48 degrees ± 2.22 degrees, 2.14 degrees ± 1.59 degrees and 1.51 degrees ± 0.87degrees and the symptomatic shoulders 8.59 degrees ± 12.96 degrees, 6.89 degrees ± 6.36 degrees and 4.4 degrees ± 3.45 degrees respectively. In the post-operative group, asymptomatic shoulders had values of 2.09 degrees ± 1.25 degrees, 2.31 degrees ± 1.30 degrees and 2.30 degrees ± 1.31 degrees and symptomatic shoulders 2.15 degrees ± 1.30 degrees, 2.54 degrees ± 1.43 degrees and 2.89 degrees ± 2.12 degrees respectively. With respect to RPP, controls had values at 0 degrees, +30 degrees and –30 degrees of 2.49 degrees ± 1.02 degrees, 2.58 degrees ± 1.13degrees and 2.72 degrees ± 2.11 degrees. In the pre-operative group, the results for asymptomatic shoulders were 2.48 degrees ± 0.68 degrees, 0.87 degrees ± 0.51 degrees and 3.44 degrees ± 2.41 degrees and for symptomatic shoulders 5.63 degrees ± 2.05 degrees, 3.17 degrees ± 2.05 degrees and 7.56 degrees ± 6.10 degrees respectively. In the post-operative group, the results for asymptomatic shoulders were 2.85 degrees ± 1.13 degrees, 3.78 degrees ± 1.94 degrees and 2.55 degrees ± 2.11 degrees and for symptomatic shoulders 2.28 degrees ± 0.81 degrees, 5.40 degrees ± 5.91 degrees and 3.62 degrees ± 1.63 degrees respectively.
Conclusions: There were no differences between shoulders in controls and post-operative patients. Despite the small numbers, the pre-operative patients showed significant differences (p< 0.05) between shoulders in two of the six test protocols. Post-operative shoulders had means similar to controls suggesting thermo-capsular shrinkage may help regain shoulder proprioception after injuries.
The abstracts were prepared by Professor A. J. Thurston. Correspondence should be addressed to him at the Department of Surgery, Wellington School of Medicine, PO Box 7343, Wellington South, New Zealand
