Gait analysis in short-term follow-up of medial opening wedge high tibial osteotomy

Gait analysis and knee kinematics before, and 6 and 18 months after corrective valgus osteotomy

BACKGROUND

The study objective was to assess clinical outcomes and gait biomechanics in patients after 6 and 18 months after varus deformity (VD) surgical correction at knee joint (KJ).

METHOD

The study included 20 patients with medial osteoarthritis (OA) of the knee of grade 2-3 and a VD of >4°. A total of 21 surgeries were performed on the patients. Full length weight bearing (FLWB) X-ray and KJ assessments were done using the KSS, KOOS and VAS scoring systems were obtained from all the patients. Biomechanical gait parameters were captured using an inertial sensor system at timepoints before, and 6 and 18 months after surgery. Temporal and kinematic parameters of walking were analyzed.

RESULTS

The radiological parameters showed a stable VD correction. According to the KOOS, KS and VAS scores, there was a moderate dynamic improvement in the operated knee function during the study. The biomechanical parameters remained virtually unchanged throughout the entire follow-up period. In the following year, there were some subjective improvements but without any significant changes in gait biomechanics or knee kinematics.

CONCLUSIONS

Thus, the main changes in the joint clinical condition and function occur in the first 6 months after surgery. According to the study data-assessments by VAS, KOOS, and KSS-there was a moderate clinical improvement during the long-term follow-up period, however, the biomechanical changes were minor.

Gait analysis and knee joint kinematics before a and 6 month after of corrective valgus osteotomy at patients with medial knee arthritis

PURPOSE

A varus deformity (VD) of the lower limbs results in greater loading of the medial compartment of the knee joint (KJ), leading to its degenerative changes and, eventually, to progressive osteoarthritis (OA) of the joint. The aim of the study was to investigate the mid-term changes in gait biomechanics and clinical symptoms in patients with VD of KJ and OA before and six months after surgical correction.

METHODS

The study enrolled 25 patients with medial OA of grade 2-3 according to Kellgren-Lawrence and a VD of > 3°, who underwent arthroscopic lavage and debridement of the knee joint followed by corrective osteotomy. The control group included 20 healthy adults. Clinical and biomechanical assessments were done twice: immediately prior to and six months after the surgical treatment. Biomechanical parameters of gait were recorded using an inertial sensor system.

RESULTS

According to our findings, there was a statistically significant post-operative increase in the knee extension amplitude by 1.4° in female patients and an insignificant extension increase in male patients. The mean postoperative KOOS score was 66.7 points (46 to 91) in the patient group, 67.1 points (54 to 91) in males, and 59.5 points (46 to 64) in females. As early as six months after a valgus osteotomy, we already observed improved biomechanics of the KJ motions compared to pre-operative data. By that time, the swing flexion amplitude of the affected KJ had increased and became symmetrical, which had not been the case before surgery. We observed a total of three changes in the KJ kinematics after surgery: increased swing flexion amplitudes in both KJs, a decreased extension amplitude in the affected KJ, and increased first flexion amplitudes in both KJs.

CONCLUSION

According to our study, the midterm outcomes after a valgus osteotomy showed clinical improvements based on the VAS and KOOS scores, which were however less pronounced than in similar studies with a longer assessment term after surgery. We also found a significant increase in the amplitude of joint extension, but only in females. As the function of the operated joint is concerned, valgus osteotomy restored the kinematics of walking movements to a nearly normal gait with increased first and second flexion amplitudes. The function of KJ becomes symmetric though the non-operative side. Thus, the healthy and functionally more capable side is copying the movement pattern of the affected side. Hence, the non-operative leg is functioning less efficiently than it is required by the walking pace.

High Tibial Osteotomy: Review of Techniques and Biomechanics

High tibial osteotomy becomes increasingly important in the treatment of cartilage damage or osteoarthritis of the medial compartment with concurrent varus deformity. HTO produces a postoperative valgus limb alignment with shifting the load-bearing axis of the lower limb laterally. However, maximizing procedural success and postoperative knee function still possess many difficulties. The key to improve the postoperative satisfaction and long-term survival is the understanding of the vital biomechanics of HTO in essence. This review article discussed the alignment principles, surgical technique, and fixation plate of HTO as well as the postoperative gait, musculoskeletal dynamics, and contact mechanics of the knee joint. We aimed to highlight the recent findings and progresses on the biomechanics of HTO. The biomechanical studies on HTO are still insufficient in the areas of gait analysis, joint kinematics, and joint contact mechanics. Combining musculoskeletal dynamics modelling and finite element analysis will help comprehensively understand in vivo patient-specific biomechanics after HTO.