The Unstable Knee

Mullaji, Arun; Shetty, Gautam M.

doi:10.1007/978-1-4939-0566-9_10

Cited by 1 publication

(2 citation statements)

References 7 publications

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“…Quadriceps impairment reportedly induces occasional inability to fully activate the quadriceps following TKA due to voluntary quadriceps contraction disability [11][12][13][14][15][16][17][18], resulting in hyperextension and posterior dislocation of the tibia [3,[6][7][8]14,17]. Although rehabilitation exercises are generally prescribed to enhance the activation of the quadriceps following TKA [17,[31][32][33][34][35], the fundamental clinical problems have not been resolved.…”

Section: Discussionmentioning

confidence: 99%

“…However, TKA continues to exhibit failures generally related to pain, infection, osteolysis, wear, aseptic loosening, periprosthetic fracture, instability, or malalignment [5]. Additionally, muscle impairment (weakness) occasionally influences the quality of life after TKA, resulting in direct or indirect TKA failure with adverse prognosis and satisfaction [6][7][8][9][10]. In particular, quadriceps impairment is considered the main type of muscle impairment in patients who have undergone TKA [11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Potential Instability and Malfunction of Knee Joints with Vastus Medialis Impairment after Total Knee Arthroplasty

et al. 2021

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Four pairs of fresh-frozen cadaver knees (eight knees, four male knees) with a mean age of 72 ± 7 years were used for tests involving a customized simulator capable of controlling quadriceps loading conditions. The muscle force distribution of the quadriceps for the normal loading condition was applied on the basis of muscle cross-sectional area data, as previously reported (VM: 31 N; RF/VI: 49 N; VL: 45 N). To simulate vastus medialis (VM) impairment, we set the muscle force for VM in the muscle force distribution of the quadriceps at zero (VM: 0 N; RF/VI: 49 N; VL: 45 N). The joint reaction forces and moments on knee joints that underwent total knee arthroplasty (TKA) did not differ significantly according to VM impairment status for all flexion angles (p > 0.05). Nevertheless, the vectors of internal–external moments mostly showed a tendency for alteration from external to internal due to VM impairment. This tendency was evident in 9 cases in 12 total test pairs (with and without VM impairment). Furthermore, the vectors of the anterior–posterior reaction forces mostly showed a tendency to increase anteriorly due to VM impairment. This tendency was also evident in 9 cases in 12 total test pairs (with and without VM impairment). These results indicate that posterior dislocation of the tibia may be induced if VM impairment occurs after TKA. In conclusion, VM impairment in knee joints undergoing TKA may contribute to posterior dislocation of the tibia by a paradoxical roll-back with enhancements of the anterior joint reaction force and external moment during knee-joint flexion. Our findings may be valuable for understanding the mechanism of potential instability and malfunction due to VM impairment in knee joints after TKA, and may help to optimize clinical/rehabilitation training plans to improve the prognosis (stability and function) of knee joints undergoing TKA.

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