Medial and lateral gap laxity differential in computer-assisted kinematic total knee arthroplasty

2019 ◽  
Vol 101-B (3) ◽  
pp. 331-339 ◽  
Author(s):  
P. McEwen ◽  
G. Balendra ◽  
K. Doma
Keyword(s):  
Total Knee Arthroplasty ◽  
Outcome Measures ◽  
Knee Arthroplasty ◽  
Computer Assisted ◽  
Lateral Flexion ◽  
Lateral Extension ◽  
Flexion Gap ◽  
Patient Reported ◽  
Total Knee ◽  
Extension Gap

AimsThe results of kinematic total knee arthroplasty (KTKA) have been reported in terms of limb and component alignment parameters but not in terms of gap laxities and differentials. In kinematic alignment (KA), balance should reflect the asymmetrical balance of the normal knee, not the classic rectangular flexion and extension gaps sought with gap-balanced mechanical axis total knee arthroplasty (MATKA). This paper aims to address the following questions: 1) what factors determine coronal joint congruence as measured on standing radiographs?; 2) is flexion gap asymmetry produced with KA?; 3) does lateral flexion gap laxity affect outcomes?; 4) is lateral flexion gap laxity associated with lateral extension gap laxity?; and 5) can consistent ligament balance be produced without releases?Patients and MethodsA total of 192 KTKAs completed by a single surgeon using a computer-assisted technique were followed for a mean of 3.5 years (2 to 5). There were 116 male patients (60%) and 76 female patients (40%) with a mean age of 65 years (48 to 88). Outcome measures included intraoperative gap laxity measurements and component positions, as well as joint angles from postoperative three-foot standing radiographs. Patient-reported outcome measures (PROMs) were analyzed in terms of alignment and balance: EuroQol (EQ)-5D visual analogue scale (VAS), Knee Injury and Osteoarthritis Outcome Score (KOOS), KOOS Joint Replacement (JR), and Oxford Knee Score (OKS).ResultsPostoperative limb alignment did not affect outcomes. The standing hip-knee-ankle (HKA) angle was the sole positive predictor of the joint line convergence angle (JLCA) (p < 0.001). Increasing lateral flexion gap laxity was consistently associated with better outcomes. Lateral flexion gap laxity did not correlate with HKA angle, the JLCA, or lateral extension gap laxity. Minor releases were required in one third of cases.ConclusionThe standing HKA angle is the primary determinant of the JLCA in KTKA. A rectangular flexion gap is produced in only 11% of cases. Lateral flexion gap laxity is consistently associated with better outcomes and does not affect balance in extension. Minor releases are sometimes required as well, particularly in limbs with larger preoperative deformities. Cite this article: Bone Joint J 2019;101-B:331–339.

Does the Robotic Arm and Preoperative CT Planning Help with 3D Intraoperative Total Knee Arthroplasty Planning?

2018 ◽  
Vol 32 (08) ◽  
pp. 742-749 ◽  
Author(s):  
Robert C. Marchand ◽  
Nipun Sodhi ◽  
Manoshi Bhowmik-Stoker ◽  
Laura Scholl ◽  
Caitlin Condrey ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Length Of Stay ◽  
Knee Arthroplasty ◽  
Robotic Arm ◽  
Lateral Flexion ◽  
Flexion Gap ◽  
Implant Size ◽  
Total Knee ◽  
Extension Gap ◽  
Robotic Software

Although several studies highlight the advantages of robotic arm-assisted total knee arthroplasty (RA-TKA), few investigate its intraoperative outcome. Therefore, the purpose of this study was to analyze the RA-TKA's ability to assist with intraoperative correction of: (1) flexion and (2) extension gaps, as well as its ability to (3) accurately predict implant sizes. Additionally, in this RA-TKA cohort, length of stay, complications, and readmissions were assessed. A total of 335 patients who underwent RA-TKA were included. The robotic software virtually measured the intraoperative prebone cut extension and flexion gaps. Differences in medial versus lateral prebone cut extension and flexion gaps were calculated. A total of 155 patients (46%) had an extension gap difference of between –2 and 2 mm (mean, –0.3 mm), while 119 patients (36%) had a flexion gap difference of between –2 and 2 mm (mean, –0.6 mm). Postbone cut differences in medial versus lateral flexion and extension gaps were measured. Balanced knees were considered to have a medial and lateral flexion gap difference within 2 mm. The robot-predicted implant size was also compared with the final implant size. Additionally, lengths of stay, complications, and readmissions were assessed. All patients achieved a postbone cut extension gap difference between –1 and 1 mm (mean, –0.1 mm). A total of 332 patients (99%) achieved a postbone cut flexion gap difference of between –2 and 2 mm (mean, 0 mm). For 98% of prostheses, the robotic software predicted within 1 implant size the actual tibial or femoral implant size used.The mean length of stay was found to be 2 days. No patients suffered from superficial skin infection, pin site infections or fractures, soft tissue damage, and no robotic cases were converted to manual TKA due to intraoperative complications. A total of 8 patients (2.2%) were readmitted; however, none were directly related to robotic use. The robotic software and use of a preoperative computed tomography (CT) substantially helped with intraoperative planning and accurate prediction of implant sizes. Therefore, based on the results of this study, the RA-TKA device does, in fact, provide considerable intraoperative assistance.

A Prospective Randomised Control Trial Comparing Functional with Mechanical Axis Alignment in Total Knee Arthroplasty: study protocol for an investigator initiated trial

2021 ◽  
Author(s):  
Richard Steer ◽  
Beth Tippett ◽  
R Nazim Khan ◽  
Dermot Collopy ◽  
Gavin Clark
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Functional Outcomes ◽  
Medical Information ◽  
Randomised Control Trial ◽  
Computer Assisted ◽  
Patient Reported ◽  
Total Knee ◽  
Alternative Alignment

Abstract Background: A drive to improve functional outcomes for patients undergoing total knee arthroplasty (TKA) has led to alternative alignment being used. Functional alignment (FA) uses intraoperative soft tissue tension to determine the optimal position of the prosthesis within the patients soft tissue envelope. Angular limits for bone resections are followed to prevent long term prosthesis failure. This study will use the aid of robotic assistance to plan and implement the final prosthesis position. This method has yet to be compared to the traditional mechanically aligned (MA) knee in a randomised trial. Methods: A blinded randomised control trial with 100 patients will be undertaken via Perth Hip and Knee clinic. Fifty patients will undergo a MA TKA and fifty will undergo a FA TKA. Both alignment techniques will be balanced via computer assisted navigation to assess prosthetic gaps, being achieved via the initial bony resection and further soft tissue releases as required to achieve satisfactory balance. The primary outcome will be the forgotten joint score (FJS) two years after surgery, with secondary outcomes being other patient reported outcome measures, clinical functional assessment, radiographic position and complications. Other data that will be collected will be patient demography (Sex, Age, level of activity) and medical information (grade of knee injury, any other relevant medical information). The linear statistical model will be fitted to the response (FJS), including all the other variables as covariates. Discussion: Many surgeons are utilising alternative alignment techniques with a goal of achieving better functional outcomes for their patients. Currently MA TKA remains the gold standard with good outcomes and excellent longevity. There is no published RCTs comparing FA to MA yet and only two registered studies are planned or currently in progress. This study utilizes a FA technique which differs from the two studies. This study will help determine if FA TKA has superior functional results for patients.Trial registration: This trial has been registered with the Australian New Zealand Clinical Trials Registry (ANZCTR) http://www.anzctr.org.au: U1111-1257-2291, registered 25th Jan 2021. It is also listed on www.clinicaltrials.gov: NCT04748510

Posterior cruciate ligament resection in total knee arthroplasty

2019 ◽  
Vol 101-B (10) ◽  
pp. 1230-1237 ◽  
Author(s):  
Babar Kayani ◽  
Sujith Konan ◽  
Saman Horriat ◽  
Mazin S. Ibrahim ◽  
Fares S. Haddad
Keyword(s):  
Total Knee Arthroplasty ◽  
Posterior Cruciate Ligament ◽  
Knee Arthroplasty ◽  
Cruciate Ligament ◽  
Limb Alignment ◽  
Flexion Gap ◽  
Flexion Extension ◽  
Total Knee ◽  
The Mean ◽  
Extension Gap

Aims The aim of this study was to assess the effect of posterior cruciate ligament (PCL) resection on flexion-extension gaps, mediolateral soft-tissue laxity, fixed flexion deformity (FFD), and limb alignment during posterior-stabilized (PS) total knee arthroplasty (TKA). Patients and Methods This prospective study included 110 patients with symptomatic osteoarthritis of the knee undergoing primary robot-assisted PS TKA. All operations were performed by a single surgeon using a standard medial parapatellar approach. Optical motion capture technology with fixed femoral and tibial registration pins was used to assess gaps before and after PCL resection in extension and 90° knee flexion. Measurements were made after excision of the anterior cruciate ligament and prior to bone resection. There were 54 men (49.1%) and 56 women (50.9%) with a mean age of 68 years (sd 6.2) at the time of surgery. The mean preoperative hip-knee-ankle deformity was 4.1° varus (sd 3.4). Results PCL resection increased the mean flexion gap significantly more than the extension gap in the medial (2.4 mm (sd 1.5) vs 1.3 mm (sd 1.0); p < 0.001) and lateral (3.3 mm (sd 1.6) vs 1.2 mm (sd 0.9); p < 0.01) compartments. The mean gap differences after PCL resection created significant mediolateral laxity in flexion (gap difference: 1.1 mm (sd 2.5); p < 0.001) but not in extension (gap difference: 0.1 mm (sd 2.1); p = 0.51). PCL resection significantly improved the mean FFD (6.3° (sd 4.4) preoperatively vs 3.1° (sd 1.5) postoperatively; p < 0.001). There was a strong positive correlation between the preoperative FFD and change in FFD following PCL resection (Pearson’s correlation coefficient = 0.81; p < 0.001). PCL resection did not significantly affect limb alignment (mean change in alignment: 0.2° valgus (sd 1.2); p = 0.60). Conclusion PCL resection creates flexion-extension mismatch by increasing the flexion gap more than the extension gap. The increase in the lateral flexion gap is greater than the increase in the medial flexion gap, which creates mediolateral laxity in flexion. Improvements in FFD following PCL resection are dependent on the degree of deformity before PCL resection. Cite this article: Bone Joint J 2019;101-B:1230–1237

Does Posterior Condylar Offset Affect Clinical Results following Total Knee Arthroplasty?

2017 ◽  
Vol 31 (08) ◽  
pp. 754-760 ◽  
Author(s):  
Ryan Degen ◽  
Jacob Matz ◽  
Matthew Teeter ◽  
Brent Lanting ◽  
James Howard ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Outcome Measures ◽  
Knee Arthroplasty ◽  
Short Form ◽  
Clinical Results ◽  
Patient Reported Outcome Measures ◽  
Posterior Condylar Offset ◽  
Patient Reported ◽  
Posterior Condylar ◽  
Total Knee

AbstractTotal knee arthroplasty (TKA) is an effective, durable treatment for knee osteoarthritis. However, a subset of patients experiences incomplete pain relief and ongoing dysfunction. Posterior condylar offset (PCO) has previously been shown to be associated with postoperative range of motion (ROM) following TKA; however, an association with patient-reported outcome measures (PROMs) has not been established. The purpose of this study was to evaluate the association between PCO and postoperative ROM and PROMs. A retrospective review of 970 posterior-stabilized single design TKAs was performed. Preoperative and postoperative radiographs were analyzed to measure the change in PCO and anteroposterior (AP) femoral dimension. Clinical outcome measures, including Short Form-12 physical and mental component summaries, Western Ontario and McMaster Universities Arthritis Index, and Knee Society Score were reviewed to determine if these were influenced by changes in PCO and AP dimension. PCO was increased by more than 3 mm in 15.1%, maintained (within 3 mm) in 59.6%, and decreased by more than 3 mm in 25.3% of patients. Comparing between these groups, there were no significant differences in postoperative ROM or PROM. AP dimension increased in 24.4%, maintained in 47.8%, and decreased in 27.8%. Similarly, there were no significant differences in ROM or PROM between these groups. Spearman's correlation analyses failed to identify an association between PCO and ROM or PROMs. In conclusion, increasing or decreasing PCO or AP femoral dimension with this PS TKA design did not significantly affect postoperative ROM or PROM. Similarly, maintenance of PCO within one implant size with this system compared with optimal sizing had no deleterious effect on TKA outcomes.

scholarly journals The Disproportionate Increase of the Intraoperative Flexion and Extension Gap Space after Posterior Cruciate Ligament Resection in Total Knee Arthroplasty

2021 ◽  
Vol 10 (18) ◽  
pp. 4228
Author(s):  
Kao-Chang Tu ◽  
Han-Ting Shih ◽  
Shih-Chieh Tang ◽  
Cheng-Hung Lee ◽  
Wei-Jen Liao ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Posterior Cruciate Ligament ◽  
Knee Arthroplasty ◽  
Cruciate Ligament ◽  
Open Chain ◽  
Flexion Gap ◽  
Closed Chain ◽  
Before And After ◽  
Total Knee ◽  
Extension Gap

Purpose: Maintaining gap balance is critical for total knee arthroplasty (TKA). This study aimed to elucidate if the extension–flexion gaps would be changed with posterior cruciate ligament (PCL) intact (PI) and PCL resection (PR) during TKA. The flexion gaps were measured using two methods, open-(Fo) and closed-chain position (Fc), based on the definition of kinetic chain position, respectively. Methods: This retrospective study enrolled a total of 33 patients who underwent posterior-stabilized (PS) TKA for symptomatic advanced osteoarthritis of knees. After bone cuts were completed, the extension–flexion gaps before and after PCL resection during TKA were measured using a calibrated tensioning device set at a 100 Nm distraction force. To further differentiate the effect of thigh weight on the 90° flexion gap, two varied methods of examination, either in closed chain (Fc) or open chain (Fo) were performed. Results: The increases in the 90° knee flexion gap after PCL resection were measured by both methods, i.e., ΔFc (PR-Fc—PI-Fc): 2.04 ± 2.06 mm, p < 0.001; and mean ΔFo (PR-Fo—PI-Fo): 1.64 ± 1.36 mm, p < 0.001. However, there were no differences between ΔFc and ΔFo before and after PCL resection. A greater amount of flexion gap was identified in open chain than in closed chain after PCL resection, and the PR-Fo and PR-Fc were 14.36 ± 3.13 and 11.40 ± 3.47 (p < 0.001), respectively. Conclusions: The resection of PCL during TKA distinctly increased the flexion gap, but not the extension gap. This disproportionate increase of the gap will cause a gap balance mismatch. The tensioning maneuver in open-chain was more effective to detect the gap differences than in closed-chain before and after PCL resection during TKA.

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