Open cheilectomy is an established surgical treatment for hallux rigidus. Cheilectomy is now being performed using minimally invasive(MIS) techniques. In this prospective study we report the outcome of minimally invasive cheilectomy comparing the results with a matched group who had cheilectomy using standard open procedure.

Prospective study of 47 patients. 22 patients had MIS cheilectomy between March 2009 and September 2010. We compared the outcome with a matched group (25 patients) who had open cheilectomy. Functional outcome was assessed using the Manchester Oxford Foot and ankle questionnaire (MOXFQ). The MOXFQ is a validated 16-item, patient-generated questionnaire designed to be self-completed and used as an outcome measure for foot surgery. It comprises three domains foot pain, walking and standing problems and social interaction. Total score ranges from 0 (best score) to 64 (worst score). Patients completed preoperative and postoperative questionnaires. Patients’ satisfaction and complications were recorded.

In the MIS group, the median follow up was 11 months (4–23. The median preoperative MOXFQ score was 34/64(23) and the median postoperative score was 19/64 (p value <0.02) In the open group the median follow up was 17 months (9–27). The median preoperative MOXFQ score was 35/64 and the median postoperative score was 7.5/64 and this difference was statistically significant (<0.0001). There were three failures in the open group (Fusion) compared to none in the MIS.

MIS cheilectomy is an effective alternative procedure with satisfactory functional outcome and high patient satisfaction. Results are comparable to the standard open cheilectomy with a lower apparent failure rate. The results of our randomised controlled trial comparing MIS cheilectomy to open cheilectomy are awaited.

The anterior femoral cortical line (AFCL) is an anatomical landmark which has been used by the senior author for 20 years to assess femoral rotation in over 4000 TKR's. The AFCL describes the alignment of the anterior cortex of the distal femur proximal to the trochlear articular cartilage.

The AFCL was compared with the surgical epicondylar (SEA), anteroposterior (Whiteside's line) and posterior condylar (PC) axes using 50 dry-bone cadaveric femora, 16 wet cadaveric specimens, 50 axial MRI's and 58 TKR patients intra-operatively.

In the dry-bone/cadaveric femora (measuring relative to the SEA the AFCL and Whiteside's AP axis were 1° externally rotated and the PC axis was 1° internally rotated. By MRI (relative to the SEA) the AFCL was 8° internally rotated, Whiteside's was 2° externally rotated and the PC axis was 3° internally rotated. In the clinical study (measuring relative to a perpendicular to Whiteside's line alone) the AFCL was 4° degrees internally rotated, which equates to 2-3° of internal rotation relative to the SEA.

The AFCL is another axis, completing the ‘compass points’ around the knee. It may prove particularly useful when one or all of the other reference axes are disturbed such as in revision TKR, lateral condylar hypoplasia or where there has been previous epicondylar trauma. We suggest building in 5° external rotation with respect to the anterior femoral cortical line for femoral component rotation.