Opening-wedge High Tibial Osteotomy (HTO) has been shown to be an effective procedure to treat mild to moderate osteoarthritis of the medial compartment of the knee in active individuals. It has also become a mandatory surgical adjunct to articular cartilage restoration when there is preoperative mal-alignment. However, its efficacy is directly correlated with the accuracy of the correction, which must be within 3° of the preoperative target. Achieving this goal is a significant challenge with conventional techniques. Therefore, computer-assisted navigation protocols have been developed; however, they do not adequately address the technical difficulties associated with this procedure. We present an integrated solution dedicated to the opening-wedge HTO. Advantages to the technique we propose include: 1) a minimum number of implanted bone trackers, 2) depth control of the saw, 3) improved 3-D accuracy in the location of the lateral tibial hinge, and 4) micrometric adjustment of the degree of correction. The proof of concept has been completed on all six specimens. The following key points have been validated: a) Compatibility with a minimally-invasive (5–6 cm) surgical incision b) The compact navigation station can be placed close to the operative field and manipulated through a sterile draping device c) Only two trackers are necessary to acquire the required landmarks and to provide 3-D control of the correction. These can be inserted within the surgical wound without any secondary incisions d) The optimised guide accurately controlled the external tibial hinge in all six cases e) The implant cavity could be milled effectively f) The distractor used to complete the desired realignment maintained stability of the distraction until final fixation with the PEEK implant g) The PEEK implant could be fixed to the tibia with excellent stability in a low-profile fashion. The solution presented here has the potential to help surgeons perform a medial opening-wedge HTO more safely and accurately. This will likely result in an increase in the number of HTOs performed for both isolated medial compartment osteoarthritis as well as for lower extremity realignment in association with cartilage restorative procedures.

Movement dysfunction resulting in a knee valgus position during weight bearing activity is associated with increased risk of Anterior Cruciate Ligament injury and Patellofemoral Pain Syndrome especially in young active females. In clinical practice determining the critical knee flexion angle (CKFA) during a single leg squat (SLS) test is used to assess this dysfunction, yet its reliability is unknown. This study aimed to determine rater agreement in determining the presence of knee valgus movement (yes/no) during a SLS test in recreational females (n = 16, age 24.3 ±7.9 yrs, height 165.7±4.8m, mass 62.5±6.4kg) and the intra and inter-rater reliability of measuring CKFA using SiliconCoach™. Three experienced physiotherapists viewed 48 randomised SLS test videos. One physiotherapist repeated the viewing for test-retest analysis. Test-retest agreement for rating SLS test was acceptable (weighted kappa (k) = 0.667). Inter-rater agreement was moderate to substantial (weighted k = 0.284–0.613). Intra-rater reliability of CKFA was acceptable for all three raters (ICC>0.6). Inter-rater absolute reliability was below 5% of the mean CKFA (SEM 4.26 degrees). As previous research reports intra-rater agreement is better than inter-rater agreement when assessing movement dysfunction during functional activity via visual rating. Intra-rater within session and between session reliability for measuring the CKFA using SiliconCoach™ was acceptable and better than inter-rater reliability. Further research is needed to assess the concurrent and construct validity of the protocols used in this study. It is recommended that qualitative research be performed to identify factors that affect physiotherapist's rating of functional activities.