With the approval of institutional review board,
this prospective study involved patients who had failed non-operative medical management for tennis elbow.
A diagnostic ultrasound was performed as baseline before the procedure.
The primary outcome measures were Disabilities of the Arm,
Shoulder and Hand (DASH) score and Visual analogue scale (VAS) score which were administered with ultrasound examination performed at the follow-up interval of 3 months,
6 months and 36 months after procedure.
The diagnostic ultrasound was performed by a musculoskeletal radiologist using high frequency transducer.
The ultrasound assessment comprised thickness of tendon,
presence of hypoechoic area,
hypervascularity of the tendon and neovascularity of the paratenon.
The latter 3 were scored using an ordinal scale.
1.
Thickness of tendon
This was measured as the perpendicular distance from the superficial surface of the tendon to the interface between tendon and cortical surface of the lateral epicondyle.
2.
Hypoechoic area
The hypoechoic areas within the proximal common extensor tendon with marked attenuation of the normal echogenic fibrillar pattern were identified.
A semi-quantative scoring system was used.
The sonographic appearance of this grading is shown in Fig. 1 with the hypoechoic area demarcated in Fig. 2
Hypoechoic area
|
Absent
|
0
|
<30%
|
1
|
30-50%
|
2
|
>50%
|
3
|
3.
Hypervascularity
The tendon was evaluated with colour flow imaging to document raised vascularity with the substance of the tendon.
A semi-quantitative scoring system was used.
The sonographic appearance of this grading is shown in Fig. 3 .
Hypervascularity
|
absent
|
0
|
mild <20%
|
1
|
moderate 20-80%
|
2
|
severe >80%
|
3
|
4.
Paratenon neovascularity
The relative vascularity of the paratenon layer was documented with colour-flow imaging and a semi-quantitative scoring system used.
The sonographic appearance of this grading is shown in Fig. 4 .
Paratenon neovascularity
|
absent
|
0
|
mild
|
1
|
moderate
|
2
|
severe
|
3
|
Statistical analysis of the outcome scores and observed sonographic parameters was performed using SPSS (Chicago,
Illinois).
A p value of <0.05 was considered statistically significant.
The novel percutaneous tenotomy was carried out with a proprietary device (Fig. 5) which delivered focussed,
calibrated ultrasonic energy via a disposable double-lumen 19G probe into the hypoechoic area within the tendon.
The micro resection has mechanistic similarities to established phacoemulsification technology used in cataract removal (Fig. 6 ).
Using aseptic technique,
the probe was guided into the hypoechoic area within the tendon before microresection was performed (Fig. 7).