How proprioception changes before and after total knee arthroplasty: A systematic review

BackgroundProprioception is one of the most significant factors in balance, joint stability, graceful movement, coordination, and injury prevention. It involves a wide set of receptors located within joints, muscles, and tendons. Given the neurophysiological processes involved in proprioception response are multiple and complex, there is not one single method to measure it. Particularly, proprioception of the knee joint, whether it is healthy, affected by osteoarthritis, or after replacement, is the most investigated by in literature.Research questionThis review addresses the analysis of proprioception in the knee joint before and after total knee arthroplasty (TKA). The aim is to obtain an overview of the proprioceptive skills in subjects who suffered from osteoarthritis and were subjected to knee replacement, evaluating changes in proprioception before and after the surgery.MethodsThe research was conducted within four databases: Web of Science®, PubMed Central®, Cochrane®, and PEDro®, between January 2008 and February 2018. Accurate exclusion criteria and selection strategy were applied to screen the 170 articles found.ResultsUltimately, 13 papers were fully evaluated and included in this review, divided into two classes: i) works directly measuring proprioception, ii) studies indirectly evaluating proprioception. Contrasting results emerged from the analysis, and no consensus was found in the literature about the improvement or worsening in proprioception before and after TKA.SignificanceSince currently there is high variability in methods, protocol and parameters used to evaluate knee proprioception, further investigations based on a consistent dataset, a well-defined protocol, measurable outcomes, timeline follow-ups, and rehabilitation programs should be performed in order to obtain reliable results on the effects of TKA on knee proprioception and balance.     

Computerized tomography assessment of femoral and tibial rotation in total knee prosthesis

PURPOSE: CT assessment of the axial deviation of the femoral and tibial prosthetic components in total knee arthroplasty. MATERIAL AND METHODS: January to July 1999, seventeen patients, 10 males and 7 females, mean age 66 years (standard deviation +/- 4) were examined after total knee arthroplasty. Exclusion criteria were prosthesis loosening and severe (equal or superior to 7 degrees) varus or valgus deviation. All patients were examined with knee radiography in the standing position completed by axial projections of patella and by CT scanning. We used a modification of Berger technique and carried out comparative CT scans extended lower limbs and acquisitions perpendicular to the mechanical axis of the knee, from the femoral supracondylar region down to the plane crossing the distal end of the tibial prosthetic component. Reference lines were then drawn electronically on given scanning planes to reckon the axial deviation of the femoral and tibial prosthetic components. RESULTS: Six patients, one female and 5 males, with normal rotational values of femoral and tibial prosthetic components presented no clinical symptoms. Eight patients, 4 females and 4 males, with abnormal values presented the following clinical symptoms: medial impingement, (incomplete) dislocation patella, and lateral instability. One female patient with a normal rotational value of femoral prosthetic component and an altered value of tibial prosthetic component presented medial impingement. Finally two patients, one female and one male, were absolutely asymptomatic although the rotational values of the two prosthetic components were beyond the normal range. CONCLUSIONS: Total knee arthroplasty is presently a standard treatment for many conditions involving this joint. There are several possible postoperative complications, namely fractures, dislocations (a)septic loosening and femoropatellar instability. The latter condition is the most frequent complication among implant failures and is caused by bad orientation of the femoral and tibial components on frontal and axial planes. We measured the orientation of the prosthetic components introducing a CT procedure which modifies the uniarticular with four scans introduced by Berger. The new method uses Berger's parameters and the CT study of both joints by means of Helical CT. With a single examination lasting less than 4 minutes and with the patient in a more comfortable position, we can obtain: 1) comparative and simultaneous assessment of the contralateral joint; 2) several scans to better define Berger's parameters and to accomplish measurement of the rotational deviation with higher precision and markedly decreasing the error margin. The analysis of the results confirms the international literature findings and especially the fundamental importance in positioning both prosthetic components within normal values, as emphasized by the relationship between the clinical symptoms and the rotational degree of the femoral and tibial prosthetic components.     

Mechanical axis-derived femoral component rotation in extramedullary total knee arthroplasty: a comparison between femoral transverse axis and transepicondylar axis

Purpose  

Correct rotational alignment of the femoral component is paramount to the success of total knee arthroplasty, but debate continues as to which method is the most reliable. The purpose of this study was to evaluate mechanical axis-derived rotational axis of the femoral component using an extramedullary femoral alignment guide system.     

The effect of femoral component rotation on the kinematics of the tibiofemoral and patellofemoral joints after total knee arthroplasty

Purpose  

Complications after total knee arthroplasty (TKA) often involve the patellofemoral joint, and problems with patellar maltracking or lateral instability have sometimes been addressed by external rotation of the femoral component. This work sought to measure the changes of knee kinematics caused by TKA and then to optimise the restoration of both the patellofemoral and tibiofemoral joint kinematics, by variation of femoral component internal–external rotation.     

Computer-assisted surgery improves rotational positioning of the femoral component but not the tibial component in total knee arthroplasty

Purpose

Computer-assisted surgery (CAS) may facilitate better positioning of total knee arthroplasty (TKA) along the coronal and lateral axes; however, there are doubts as to its usefulness in the rotational plane.

Methods

This is a prospective study of 95 TKAs comparing two groups: the CAS group and the standard equipment group. The series comprises 95 cases. A radiography of the lower limb and computer tomographies (CTs) of the femoral condylar region, the proximal end of the tibia and the ankle were performed to measure rotational angulation. A month after TKA surgery, the radiography and the CTs were repeated to analyze the position of the prosthetic components in the rotational plane.

Results

In the coronal axis, both CAS and mechanical technique improved femoro-tibial alignment, but when there are preexisting deformities ≥4°, CAS obtains better results. A strong correlation (R = 0.94, p = 0.001) was observed between the mean rotational axis measured with CT in the tibial plateau and that measured from the axis of the ankle. The mean initial femoral rotation of the complete series was 6.7° and 2.7° at 1-month follow-up (p < 0.001). In the standard instrumentation group, the femoral rotation went from 6.8° to 2.3°, whereas in the CAS group the femoral rotation went from 6.5° to 3.1° (p = 0.039), which is very close to the ideal 3° angle of external rotation. Tibial rotation changed by 5.28° for the entire patient population, but no differences were found when comparing CAS and standard instrumentation.

Conclusion

CAS improves frontal alignment in TKA, especially in the presence of preoperative deformities. In the femoral component, navigation most closely replicated the ideal 3° external rotation of the femoral component, but tibial rotation did not differ when comparing CAS to standard instrumentation.

Level of evidence

II.     

The anterior surface of the femur as a new landmark for femoral component rotation in total knee arthroplasty

Femoral component rotation is very important in avoiding complications and maximizing knee function following total knee arthroplasty. There is continuing debate over the most accurate axis to select intraoperatively to obtain the best results. There is considerable doubt over the ability of commonly used bony landmarks to produce a line parallel to the flexion–extension axis of the femur, either due to anatomical variation or due to poor reproducibility of the axes. Computer navigation was used to accurately measure the relative rotation indicated intraoperatively between bony landmarks, including a previously uninvestigated axis on the anterior surface of the femur. Measurements were taken during 193 total knee arthroplasties. There was a significant association between the Whiteside’s Line and the axis on the anterior surface of the femur. The Posterior Condlylar Axis was extremely variable when compared with the other measurements, with a wide range centered on a mean value of 4.1° internally rotated to the perpendicular of Whiteside’s Line. There were significant differences in both the Posterior Condylar Axis and Anterior Femoral Axis when comparing varus and valgus knees. The Posterior Condylar Axis was shown to be an inconsistent measurement in comparison to other bony landmarks, particularly in valgus knees. The strong correlation between the Whiteside’s Line and the Anterior Femoral Axis raises the possibility that the Anterior Femoral Axis maybe a useful landmark in identifying correct femoral component rotation.     

Trunk control,motion and alignment after total knee arthroplasty: a systematic review and meta-analysis

BackgroundTrunk control improves mobility, balance and quality of life early after total knee arthroplasty (TKA) and is therefore considered an important parameter during the recovery process. However, little is known about trunk control, motion and alignment after TKA. Increasing our understanding aids in optimizing treatment strategies to enhance functional mobility after TKA.Research questionDoes trunk control, motion and alignment return to normal after TKA and is this related to functional mobility?MethodsFive scientific databases were searched until July 2021. Eligibility criteria consisted of outcomes assessing trunk control and alignment in a population of adults undergoing TKA. Two reviewers independently screened studies and risk of bias was assessed by Mixed Methods Appraisal Tool (MMAT). Meta-analysis was performed for subgroups gait and alignment.ResultsOf the 362 studies retrieved, 24 were included. Study designs were cohorts with mixed methods (pre-post treatment, case-control and case-case) and three randomized controlled trials. The mean MMAT score was 75%, corresponding to low bias. In total 1178 patients and 197 controls were included. Results showed that pre-operative trunk motion was characterized by increased amplitudes in all three planes and altered alignment which did not all return to normal after TKA. Frontal plane motion and alignment recovered faster than the sagittal and transversal plane. Although pelvic tilt improved after surgery, sagittal imbalance (anteriorly shifted trunk position) was still present.SignificanceRecovery of trunk motion after TKA is time-, speed- and technique-dependent. The observed differences in trunk motion with the healthy controls persisted after TKA. This indicates that incorporating a full biomechanical chain approach, including trunk motion and gait-retraining exercises with a strong focus on postural alignment could improve functional mobility after TKA. Limited studies are available assessing trunk control and trunk motion during functional tasks besides walking which warrant further investigation.     

One-stage versus two-stage exchange arthroplasty for infected total knee arthroplasty: a systematic review

Purpose

Infection complicating total knee arthroplasty (TKA) has serious implications. Traditionally the debate on whether one- or two-stage exchange arthroplasty is the optimum management of infected TKA has favoured two-stage procedures; however, a paradigm shift in opinion is emerging. This study aimed to establish whether current evidence supports one-stage revision for managing infected TKA based on reinfection rates and functional outcomes post-surgery.

Methods

MEDLINE/PubMed and CENTRAL databases were reviewed for studies that compared one- and two-stage exchange arthroplasty TKA in more than ten patients with a minimum 2-year follow-up.

Results

From an initial sample of 796, five cohort studies with a total of 231 patients (46 single-stage/185 two-stage; median patient age 66 years, range 61–71 years) met inclusion criteria. Overall, there were no significant differences in risk of reinfection following one- or two-stage exchange arthroplasty (OR ?0.06, 95 % confidence interval ?0.13, 0.01). Subgroup analysis revealed that in studies published since 2000, one-stage procedures have a significantly lower reinfection rate. One study investigated functional outcomes and reported that one-stage surgery was associated with superior functional outcomes. Scarcity of data, inconsistent study designs, surgical technique and antibiotic regime disparities limit recommendations that can be made.

Conclusion

Recent studies suggest one-stage exchange arthroplasty may provide superior outcomes, including lower reinfection rates and superior function, in select patients. Clinically, for some patients, one-stage exchange arthroplasty may represent optimum treatment; however, patient selection criteria and key components of surgical and post-operative anti-microbial management remain to be defined.

Level of evidence

III.

     

Varus femoral and tibial coronal alignments result in different kinematics and kinetics after total knee arthroplasty

Purpose

Abnormal knee motion under various conditions has been described after total knee arthroplasty (TKA). However, differences in kinematics and kinetics of knees with varus femoral versus varus tibial alignment have not been evaluated. It was hypothesized that varus femoral and tibial alignments have the same impact on knee motion.

Methods

A musculoskeletal computer simulation was used. Femoral and tibial alignment in the coronal plane was each varied from neutral to 5° of varus in 1° increments. Lift-off, defined as an intercomponent distance of >2 mm, and tibiofemoral contact forces were evaluated during gait up to 60° of knee flexion. Knee kinematics and contact stresses were also examined during squat, with up to 130° of knee flexion.

Results

During gait, lift-off occurred readily with more than 3° of varus tibial alignment and slight lateral joint laxity. In contrast, lift-off did not occur with varus femoral or tibial alignment of up to 5° during squat. Peak medial contact forces with varus femoral alignment were approximately twice those observed with varus tibial alignment. The lowest points of the femoral condyles moved internally with varus femoral alignment, contrary to the kinematics with neutral or varus tibial alignment. On the other hand, there was femoral medial sliding and edge loading against the tibia in mid-flexion with varus tibial alignment.

Conclusion

Varus femoral alignment affects the non-physiological rotational movement of the tibiofemoral joint, whereas varus tibial alignment causes medial–lateral instability during mid-flexion. Varus femoral and tibial alignments might lead to post-TKA discomfort and unreliability.

     

Influence of tibial rotation in total knee arthroplasty on knee kinematics and retropatellar pressure: an in vitro study

Purpose

Although continuous improvements have been made, there is still a considerable amount of unsatisfied patients after total knee arthroplasty (TKA). A main reason for this high percentage is anterior knee pain, which is supposed to be provoked by post-operative increased retropatellar peak pressure. Since rotational malalignment of the implant is believed to contribute to post-operative pain, the aim of this study was to examine the influence of tibial component rotation on knee kinematics and retropatellar pressure.

Methods

Eight fresh-frozen knee specimens were tested in a weight-bearing knee rig after fixed-bearing TKA under a loaded squat from 20° to 120° of flexion. To examine tibial components with different rotations, special inlays with 3° internal rotation and 3° external rotation were produced and retropatellar pressure distribution was measured with a pressure-sensitive film. The kinematics of the patella and the femorotibial joint were recorded with an ultrasonic-based motion analysis system.

Results

Retropatellar peak pressure decreased significantly from 3° internal rotation to neutral position and 3° external rotation of the tibial component (8.5 ± 2.3 vs. 8.2 ± 2.4 vs. 7.8 ± 2.5 MPa). Regarding knee kinematics femorotibial rotation and anterior–posterior translation, patella rotation and tilt were altered significantly, but relative changes remained minimal.

Conclusion

Changing tibial rotation revealed a high in vitro influence on retropatellar peak pressure. We recommend the rotational alignment of the tibial component to the medial third of the tibial tuberosity or even more externally beyond that point to avoid anterior knee pain after TKA.

     

股骨滑车轴作为全膝置换股骨旋转截骨轴线的可靠性评估

目的 研究股骨滑车轴( trochleare line,TL)作为全膝置换股骨假体旋转对位标志的可靠性. 方法 对89例正常成人膝关节CT扫描,在横断面图像上定位外科经股骨上髁轴(surgical transepicondylar axis,STEA)、股骨后髁轴(posterior condylar line,PCL)和TL.测量TL相对于STEA旋转的角度(TSA)、TL相对于PCL旋转的角度(TPA)、PCL相对于STEA旋转的角度(PCA),比较它们相对STEA的可靠性. 结果 TSA为(6.77±3.12)°、TPA为(4.22±2.64)°、PCA为(2.95±1.77)°,三种角度2×2析因分析性别、左右差异均无统计学意义(P＞0.05),秩和检验( HC=66.837,P＜0.01)结果 提示三组角度总体分布不同.TSA的变异系数较小,但标准差较大(3.12°).结论 TL仅可作为股骨假体旋转对位的辅助性标志.     

The anterior trochlear line as a reference for femoral component positioning in total knee arthroplasty

Purpose  

A new radiographic method using the anterior and posterior femoral condyles as a landmark to determine the rotational alignment of the femoral component in TKA had been developed.     

Native femoral sulcus as a guide for the position of the femoral component in primary total knee arthroplasty

A prospective randomized study was conducted to evaluate the effects of using the native femoral sulcus as a guide for the positioning of the femoral component in primary total knee arthroplasty (TKA), especially for patellar tracking. Between 2000 and 2002, 420 cases of primary TKA were collected. All the TKAs were performed with the same approach. The cases were randomly separated into two groups. In group 1 (consisting of 202 knees), the femoral insertion of the posterior cruciate ligament and the midline of the lateral–medial femoral condyles were used as a guide for the midline position of the femoral component; while in group 2 (consisting of 218 knees), the native femoral sulcus was used as the guide for the femoral component. Intraoperatively, no thumb technique was used to check the patellar tracking. In group 1, 16 knees (7.9%) received lateral retinacular releases, while none received lateral retinacular release in group 2 (P<0.0001). The average (range) follow-up period was 40 (30–56) months. In postoperative radiographic evaluation, two knees (1%) of lateral tilting of the patella were noted in group 1; while two knees (0.91%) of lateral tilting of the patella were noted in group 2 (P=0.751). In conclusion, native femoral sulcus could be a very effective and simple guide for the medial-lateral position of the femoral component, especially for patellar tracking.The prostheses used in this series were all Nexgen LPS-FLEX PCL Substituting (Zimmer, Warsaw) prostheses.     

Referencing the sulcus line of the trochlear groove and removing intraoperative parallax errors improve femoral component rotation in total knee arthroplasty

Purpose

Firstly, to assess and compare the accuracy and reproducibility of the sulcus line compared to Whiteside’s line. Secondly, to assess the accuracy of intraoperative techniques for using the rotational alignment of the trochlear groove to set femoral rotation. Thirdly, to assess the reproducibility of a trochlear alignment guide which removes parallax errors that occur when projecting the sulcus line onto the surface of the femur. Finally, to measure the result of combining the geometrically accurate sulcus line and the posterior condylar axis.

Methods

Three surgeons measured eight rotational angles on ten cadaveric femora. This included Whiteside’s line, the sulcus line and the techniques in which they can be referenced during surgery.

Results

Relative to the anatomical epicondylar axis, the sulcus line (mean ?2.8°, SD 2.0°, range ?5.4° to 0.8°) had significantly lower variance (F = 5.16, p = 0.036) than Whiteside’s line (mean ?2.0°, SD 3.7°, range ?6.0° to 3.4°). The trochlear alignment guide produced the best results of the intraoperative techniques by maintaining the accuracy of the sulcus line and projecting it onto the distal cut surface of the femur without change in rotational angle.

Conclusion

The sulcus line is more accurate and reproducible than Whiteside’s line. Removing parallax errors during surgery improves femoral component rotation. The trochlear alignment guide produced accurate results suggesting that it may be beneficial in a clinical setting. Averaging the sulcus line and posterior condylar axis on the cut surface of the femur improved accuracy over the individual landmarks. Femoral component malrotation is a common cause of patient dissatisfaction and revision surgery. By isolating the rotational alignment of the trochlear groove using the sulcus line, and maintaining its accuracy with an intraoperative guide, we can decrease the risk of femoral component malrotation and improve patient outcomes.