Frontal plane biomechanics of the operated and non-operated knees before and after unilateral total knee arthroplasty.

BACKGROUND: After unilateral total knee arthroplasty, frontal plane loading patterns on the operated knee remain pathological in the long term, but it is unclear how they change in the early postoperative period. Additionally, researchers have suggested that the non-operated knee bears greater frontal plane loads postoperatively, but this effect is unclear. The objective of the present study was to compare the preoperative and early postoperative frontal plane loading patterns of both knees after unilateral total knee arthroplasty. METHODS: Fifty patients with end-stage knee osteoarthritis were examined prior to and six weeks after surgery. Patients underwent a three-dimensional gait analysis that determined the frontal plane loading patterns of knee varus angle and knee adduction moment during gait, and completed self-evaluative questionnaires and functional tests. FINDINGS: There were no significant loading differences between limbs preoperatively. The operated knee showed large reductions in varus angle and adduction moment after surgery (all p<0.001). The non-operated knee showed no increases in varus angle or adduction moment, but did show a small reduction in the adduction moment (p<0.001). Both knees showed reduction in pain after surgery (p<0.001) and the operated Knee Society Score improved after surgery (p=0.01). INTERPRETATION: Total knee arthroplasty reduces frontal plane loading in the operated knee and does not worsen frontal plane loading in the non-operated knee. Therapy after surgery should focus on retaining the reduction in knee adduction moment in the operated knee and preventing further worsening loading patterns in the non-operated knee.

TENS to the posterior aspect of the legs decreases postural sway during stance.

The purpose of this study was to examine the effect of Transcutaneous Electrical Nerve Stimulation (TENS) applied to the posterior aspect of the legs, on postural sway during stance. Thirty healthy subjects were tested while standing on a force platform under four stimulation conditions: no TENS, bilateral TENS, and unilateral left and right TENS. Thirty-second long tests, employing detection threshold amplitudes, were performed in three blocks. In each block, the four conditions were applied both with and without vision in a random order. The results indicate that the application of TENS brought about a decrease in postural sway as expressed by average sway velocity, in addition to a decrease in the absolute values of maximal and minimal medio-lateral and anterior-posterior velocity. Thus, similar to sub-threshold random electrical noise, it appears that the application of low-amplitude TENS to the lower limbs decreases postural sway during stance. Considering the ease of TENS application and the high prevalence of postural disorders, the potential clinical significance of this observation is to be determined by further studies.

Functional recovery following pertrochanteric hip fractures fixated with the Dynamic Hip Screw vs. the percutaneous compression plate.

The Dynamic Hip Screw (DHS) is currently the most frequently used implant for the treatment of pertrochanteric hip fractures. The Percutaneous Compression Plate (PCCP) is a recently developed, alternative device that involves minimal invasive surgery. The objective of the present study was to compare functional recovery following these two surgical procedures. A total of 76 consecutive elderly subjects (mean age and standard deviation, 80.6 +/- 5.5) following pertrochanteric hip fracture fixation were evaluated prospectively. Functional recovery was assessed 3 and 12 weeks and 2 years following surgery. Differences between groups 3 weeks postsurgery were found only in pain level during ambulation and in the weight-bearing capability of the operated extremity, which were both in favor of the PCCP. By 3 months, both groups had improved in all measures, but did not reach their preinjury level of independence. However, the PCCP group ambulated with fewer assistive devices and demonstrated better recovery of basic activities of daily living (BADL). While the majority of the subjects from both groups ambulated independently 2 years postsurgery, the PCCP group exhibited less pain during ambulation, was more independent in ADL, and required fewer assistive devices for ambulation. To summarize, the PCCP presents enhanced short- and long-term recovery of functional abilities in comparison to DHS. However, given the limited number of patients, further studies are necessary to substantiate these results.