Pressure algometry is an excellent tool to measure knee pain relief after a closing-wedge high tibial osteotomy.

PURPOSE

The aim of this study was to assess the utility of pressure algometry (PA) to measure pain relief in the medial part of the knee after a closing-wedge high tibial osteotomy (CWHTO).

METHODS

Prospective study including 44 CWHTO. Pain relief was evaluated with the visual analogue scale (VAS) and PA, a radiological study was done and a functional assessment was carried out with the KSS preoperatively, at 6-months and at 1-year after the surgery. PA was applied to the medial and lateral part of the knee and to the infra-clavicular fossa as a control point.

RESULTS

The mechanical femorotibial angle was changed from 172.2° (SD2.2) to 180.6° (SD2.6) (p=0.00). KSS Knee improved from 53.4 (SD11.2) to 92.8 (SD7.3) (p=0.00), KSS Function from 69.4 (SD9.3) to 93.1 (SD8) (p=0.00). The VAS went from 6.84 (SD1.5) to 2.5 (SD2.1) (p=0.00) at the 1-year follow-up. The pressure pain threshold (PPT), measured with PA in the medial part of the knee also improved from 348.8kPa (SD159.3) to 447.1kPa (SD218.8) (p=0.01). However, the PPT in the lateral part of the knee and in the sub-clavicular fossa remained the same from the preoperative period to 6-months and 1-year, postoperatively. Neither were there any differences between the 6-month and 1-year postoperative values in terms of the different functional, radiological and pain relief obtained.

CONCLUSION

The pain relief obtained after a CWHTO in the medial part of the knee can be measured by using PA. Furthermore, the functional and pain improvement obtained at 1-year follow-up is no better than those obtained at 6-months postoperatively.