Kinesiologic Measurements of Functional Performance before and after Double Compartment Marmor Knee Arthroplasty

Background: A major disadvantage of current spacers for two-stage revision total knee arthroplasty (R-TKA) is the risk of (sub-) luxation during mobilization in the prosthesis-free interval, limiting their clinical success with detrimental consequences for the patient. The present study introduces a novel inverse spacer, which prevents major complications, such as spacer (sub-) luxations and/or fractures of spacer or bone. Methods: The hand-made inverse spacer consisted of convex tibial and concave femoral components of polymethylmethacrylate bone cement and was intra-operatively molded under maximum longitudinal tension in 5° flexion and 5° valgus position. Both components were equipped with a stem for rotational stability. This spacer was implanted during an R-TKA in 110 knees with diagnosed or suspected periprosthetic infection. Postoperative therapy included a straight leg brace and physiotherapist-guided, crutch-supported mobilization with full sole contact. X-rays were taken before and after prosthesis removal and re-implantation. Results: None of the patients experienced (sub-) luxations/fractures of the spacer, periprosthetic fractures, or soft tissue compromise requiring reoperation. All patients were successfully re-implanted after a prosthesis-free interval of 8 weeks, except for three patients requiring an early exchange of the spacer due to persisting infection. In these cases, the prosthetic-free interval was prolonged for one week. Conclusion: The inverse spacer in conjunction with our routine procedure is a safe and cost-effective alternative to other articulating or static spacers, and allows crutch-supported sole contact mobilization without major post-operative complications. Maximum longitudinal intra-operative tension in 5° flexion and 5° valgus position appears crucial for the success of surgery.

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Postoperative laxity of the lateral soft tissue is largely negligible in total knee arthroplasty for varus osteoarthritis

Journal of Orthopaedic Surgery ◽

10.1177/23094990211002002 ◽

2021 ◽

Vol 29 (1) ◽

pp. 230949902110020

Author(s):

Seikai Toyooka ◽

Hironari Masuda ◽

Nobuhiro Nishihara ◽

Takashi Kobayashi ◽

Wataru Miyamoto ◽

...

Keyword(s):

Total Knee Arthroplasty ◽

Soft Tissue ◽

Knee Arthroplasty ◽

Mechanical Axis ◽

Varus Deformity ◽

Varus Knee ◽

Before And After ◽

Knee Deformity ◽

Varus Stress ◽

Total Knee

Purpose: To evaluate the integrity of lateral soft tissue in varus osteoarthritis knee by comparing the mechanical axis under varus stress during navigation-assisted total knee arthroplasty before and after compensating for a bone defect with the implant. Methods: Sixty-six knees that underwent total knee arthroplasty were investigated. The mechanical axis of the operated knee was evaluated under manual varus stress immediately after knee exposure and after navigation-assisted implantation. The correlation between each value of the mechanical axis and degree of preoperative varus deformity was compared by regression analysis. Results: The maximum mechanical axis under varus stress immediately after knee exposure increased in proportion to the degree of preoperative varus deformity. Moreover, the maximum mechanical axis under varus stress after implantation increased in proportion to the degree of preoperative varus deformity. Therefore, the severity of varus knee deformity leads to a progressive laxity of the lateral soft tissue. However, regression coefficients after implantation were much smaller than those measured immediately after knee exposure (0.99 vs 0.20). Based on the results of the regression formula, the postoperative laxity of the lateral soft tissue was negligible, provided that an appropriate thickness of the implant was compensated for the bone and cartilage defect in the medial compartment without changing the joint line. Conclusion: The severity of varus knee deformity leads to a progressive laxity of the lateral soft tissue. However, even if the degree of preoperative varus deformity is severe, most cases may not require additional procedures to address the residual lateral laxity.

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Walking time measures for evaluating OA of the knee

South African Journal of Physiotherapy ◽

10.4102/sajp.v50i1.678 ◽

2019 ◽

Vol 50 (1) ◽

pp. 5-8

Author(s):

R. Marks

Keyword(s):

Functional Performance ◽

Intraclass Correlation ◽

Knee Extensor ◽

Quadriceps Strength ◽

Knee Extensor Strength ◽

Before And After ◽

Walking Tests ◽

Experimental Subjects ◽

Test Retest Reliability ◽

Walking Time

This study assessed the test-retest reliability and the sensitivity of self-paced walking time measurements for evaluating the functional performance of persons with knee osteoarthritis (OA). The 13 m timed walking tests were carried out on two separate occasions over a six-week period for 10 patients using a standardised protocol. The same measurements were recorded also for three additional patients before and after a six-week quadriceps strength training regimen. As indicated by an intraclass correlation coefficient of 0.83 with no significant intersession test differences for the group (P=0.98), the gait measurements were reliable. However, despite marked increase in knee extensor strength and significant subjective improvements in walking time for the three experimental subjects were smaller than the error of measurement. The findings suggest that regardless of reliability, measurements of self-paced level walking time might not be sufficiently sensitive for evaluating longitudinal changes in functional performance in this patient population.

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Bone Cement Solidifiliation Influence the Limb Alignment and Gap Balance during TKA

BioMed Research International ◽

10.1155/2015/109402 ◽

2015 ◽

Vol 2015 ◽

pp. 1-3 ◽

Cited By ~ 2

Author(s):

Dongquan Shi ◽

Xingquan Xu ◽

Anyun Guo ◽

Jin Dai ◽

Zhihong Xu ◽

...

Keyword(s):

Total Knee Arthroplasty ◽

Bone Cement ◽

Knee Arthroplasty ◽

Mechanical Axis ◽

Statistical Significance ◽

Mechanical Alignment ◽

Early Loosening ◽

Flexion Extension ◽

Before And After ◽

Total Knee

Introduction. Mechanical alignment deviation after total knee arthroplasty is a major reason for early loosening of the prosthesis. Achieving optimum cement penetration during fixation of the femoral and tibial component is an essential step in performing a successful total knee arthroplasty. Bone cement is used to solidify the bone and prosthesis. Thickness imbalance of bone cement leads to the deviation of mechanical alignment. To estimate the influence of bone cement, a retrospective study was conducted.Materials and Methods. A total of 36 subjects were studied. All the TKA were performed following the standard surgical protocol for navigated surgery by medial approach with general anaesthesia. Prostheses were fixed by bone cement.Results. We compared the mechanical axis, flexion/extension, and gap balance before and after cementation. All the factors were different compared with those before and after cementation. Internal rotation was reached with statistical significance (P=0.03).Conclusion. Bone cement can influence the mechanical axis, flexion/extension, and gap balance. It also can prompt us to make a change when poor knee kinematics were detected before cementation.

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