Good Alignment After Total Knee Arthroplasty Leads to Faster Rehabilitation and Better Function

Longstaff, Lee M.; Sloan, Karen; Stamp, Nikki; Scaddan, Matt; Beaver, R.J.

doi:10.1016/j.arth.2008.03.002

Cited by 330 publications

(267 citation statements)

References 15 publications

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“…Measurements denoting lateral displacement from the center point of the tibial plateau were ascribed a positive value (+), whereas measurements indicating a medial distance from the center of the tibial plateau were considered negative (À). In this study, the accepted values for normal or in-range alignment were: (1) 2°to 8°valgus for FTA [1,14,25,32,34]; (2) 0°± 3°varus/valgus for HKA [2,3,18,19,23]; and (3) the central zone for ZMA [25,27,30,36]. We determined interrater reliability by calculating the intraclass correlation coefficient (ICC) using a two-way Fig.…”

Section: Methodsmentioning

confidence: 99%

“…There are several commercially available patient-specific guides on the market using one of two basic alignment goals based on either (1) restoring the mechanical alignment [1,18,23,24,32,34], or (2) restoring the kinematic alignment [11-13, 15, 16]. In the mechanical axis model, the goals of component placement are perpendicular to the mechanical axis of the tibia and parallel to the epicondylar axis of the femur (distal femoral resection in 5°to 8°valgus) [1,18,23,24,32,34]. The historical precedent for coronal alignment after TKA originally was supported by John Insall [17], who believed restoration of alignment of the mechanical axis of the lower extremity should be through the center of the knee.…”

Section: Introductionmentioning

confidence: 99%

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Do Patient-specific Guides Improve Coronal Alignment in Total Knee Arthroplasty?

Nunley

Ellison

Zhu

et al. 2012

Clinical Orthopaedics &Amp; Related Research

207

175

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Background Coronal alignment may impact clinical outcome and survivorship in TKA. Patient-specific instrumentation has been developed to restore mechanical or kinematic axis and potentially reduce component malpositioning. Although it is clear these instruments add cost, it is unclear whether they improve alignment. Questions/purposes We determined whether the mean coronal alignment after TKA performed with conventional versus patient-specific instrumentation better restored the mechanical and kinematic axes and whether there were more outliers with one of the two methods. Methods We retrospectively evaluated 150 primary TKAs performed for osteoarthritis: Group 1 (n = 50) conventional instrumentation; Group 2 (n = 50) patientspecific instrumentation restoring the mechanical axis; Group 3 (n = 50) patient-specific instrumentation restoring the kinematic axis, and measured femorotibial angle, hipknee-ankle angle, and the zone of the mechanical axis from scout CT images taken 0 to 6 weeks postoperatively.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Do Patient-specific Guides Improve Coronal Alignment in Total Knee Arthroplasty?

Nunley

Ellison

Zhu

et al. 2012

Clinical Orthopaedics &Amp; Related Research

207

175

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“…Several studies have used a deviation of 3° from a neutral alignment as a threshold for what is acceptable for good long-term results (Jeffery et al 1991, Ritter et al 1994 and 2011, Berend et al 2004). Such a 3° threshold has also been chosen in numerous other studies investigating results after TKA (Choong et al 2009, Longstaff et al 2009, Parratte et al 2010, Huang et al 2012), and an alignment within 3° of the mechanical axis has been considered to be the gold standard (Lombardi et al 2011). Based on this, we decided to use a deviation from the neutral mechanical axis of 3° as the threshold between normally aligned and malaligned TKA knees.…”

Section: Discussionmentioning

confidence: 99%

“…Failure to restore limb alignment in total knee arthroplasty (TKA) increases the risk of revision (Jeffery et al 1991, Ritter et al 1994 and 2011, Berend et al 2004), but the effect of accurate postoperative alignment on TKA function is controversial (Lotke and Ecker 1977, Choong et al 2009, Fang et al 2009, Longstaff et al 2009, Huang et al 2012). …”

mentioning

confidence: 99%

Moderate varus/valgus malalignment after total knee arthroplasty has little effect on knee function or muscle strength

Stučinskas¹,

Robertsson²,

Širka³

et al. 2015

Acta Orthopaedica

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Background and purpose — Postoperative muscle strength and component alignment are important factors affecting functional results after total knee arthroplasty (TKA). We are not aware of any studies that have investigated the relationship between them. We therefore investigated whether coronal malalignment of the mechanical axis and/or of individual implant components would affect knee muscle strength and function 1 year after TKA surgery.Patients and methods — We included 120 consecutive osteoarthritis (OA) patients admitted for TKA. Preoperative active range of motion (ROM) of the knee, patient age, sex, and BMI were recorded and the Knee Society score (KSS) and knee joint extensor/flexor muscle strength were assessed. At 1-year follow-up, the mechanical and coronal component alignment was measured from a postoperative long standing radiograph, and ROM, KSS, and muscle strength measurements were taken in 91 patients. Functional outcome and muscle strength measurements were compared between normally aligned and malaligned TKA groups.Results — 29 of 91 TKAs were malaligned, i.e. they deviated more than 3° from the neutral mechanical axis. 18 femoral components and 15 tibial components were malaligned. Before surgery, the malaligned and normally aligned groups were similar regarding sex distribution, BMI, ROM, KSS, and muscle strength. At the 1-year follow-up, the differences between the groups regarding knee joint function and muscle strength were small, not statistically significant, and barely clinically relevant.Interpretation — Moderate varus/valgus malalignment of the mechanical axis or of individual components has no relevant clinical effect on function or muscle strength 1 year after TKA surgery.

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“…Although numerous studies have stressed the importance of a well-aligned limb mechanical axis after TKA [6,13,23], it is unclear what clinical and radiographic factors can increase the risk of limb malalignment after TKA. Based on our large series of 1500 computer-assisted TKAs, we sought to answer the following questions: (1) What are the incidence and characteristics of outliers for postoperative limb mechanical axis (HKA angle outside the conventionally acceptable range of 180°± 3°) and component alignment in TKA?…”

Section: Discussionmentioning

confidence: 99%

Which Factors Increase Risk of Malalignment of the Hip-Knee-Ankle Axis in TKA?

Mullaji

Shetty

Lingaraju

et al. 2013

Clinical Orthopaedics &Amp; Related Research

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Background Computer navigation has improved accuracy and reduced the percentage of alignment outliers in TKA. However, the characteristics of outliers and the risk factors for limb malalignment after TKA are still unclear. Questions/Purposes We therefore addressed the following questions: (1) What is the incidence and characteristics of outliers for postoperative limb mechanical axis (hip-knee-ankle [HKA] angle outside the conventional 180°± 3°range) and component alignment in TKA? And (2) what are the preoperative clinical or radiographic risk factors for limb mechanical axis malalignment in TKA? Methods We retrospectively reviewed the clinical and radiographic records of 1500 computer-assisted TKAs to identify outliers for postoperative HKA axis and component alignment and determined risk factors for malalignment. Full-length hip-to-ankle and knee radiographs were used to measure preoperative HKA angle, femoral coronal bowing, joint divergence angle, tibial subluxation, and tibial bone loss and postoperative HKA angle and femoral and tibial component angle. Results The incidence of outliers for postoperative limb mechanical axis, femoral component alignment, and tibial component alignment was 7% (112 of 1500 TKAs), 7%, and 8%, respectively, with 70% of limbs placed in excessive varus and 30% in excessive valgus. Preoperative varus deformity of more than 20°and femoral bowing of more than 5°were associated with increased risk of placing the limb mechanical axis outside the acceptable ± 3°range after computer-assisted TKA. Conclusions The presence of preoperative radiographic risk factors should alert the surgeon to increased chance of malalignment and every measure should be undertaken in such at-risk knees to ensure proper limb and component alignment and soft tissue balance.

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Good Alignment After Total Knee Arthroplasty Leads to Faster Rehabilitation and Better Function

Cited by 330 publications

References 15 publications

Do Patient-specific Guides Improve Coronal Alignment in Total Knee Arthroplasty?

Do Patient-specific Guides Improve Coronal Alignment in Total Knee Arthroplasty?

Moderate varus/valgus malalignment after total knee arthroplasty has little effect on knee function or muscle strength

Which Factors Increase Risk of Malalignment of the Hip-Knee-Ankle Axis in TKA?

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