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.
