Femoral Component Placement Research Articles

Intraoperative lateral laxity greater than 4° is associated with inferior functional improvement in posterior-stabilised total knee arthroplasty.

The study aimed to determine the impact of intraoperative lateral laxity at extension on clinical and functional outcomes 1 year after posterior-stabilised total knee arthroplasty (PS-TKA). In total, 91 varus-type osteoarthritic knees that underwent PS-TKA using the medial preservation gap technique were included. After the femoral trial component placement and patellofemoral joint reduction, the soft-tissue balance was assessed using an offset-type tensor with a 40-lb joint-distraction force. Patients were divided into the following three groups according to the intraoperative lateral laxity at extension (i.e., varus ligament balance) using the mean ± 1 standard deviation: Groups A, ≤0°; B, 0-4°; and C, >4°. The 2011 Knee Society Score (KSS) and 3-m timed up-and-go test (TUG) time 1-year postoperatively, and their improvements were compared among the groups. While significant improvements were observed in all subscales of the 2011 KSS and TUG post-TKA (p < 0.05), the improvement of functional activities and TUG time were significantly lower in Group C than in Group B (p < 0.05). However, no significant differences were observed in symptom improvement, patient satisfaction or patient expectation scores among the groups. An excessive lateral laxity (varus angle) >4° at extension was associated with lower improvement in functional ability 1-year postoperatively. Therefore, excessive intraoperative lateral laxity should be avoided in PS-TKA. Level IV.

High three-dimensional accuracy of component placement and lower limb alignment using a robotic arm-assisted system and gap-balancing instrument in total knee arthroplasty.

It was hypothesized that robotic arm-assisted total knee arthroplasty (RA-TKA) using additionally a gap-balancing instrumentation will show high accuracy in executing the planning in femoral and tibial component placement throughout the range of knee motion (ROM) during TKA surgery. Prospectively collected data were analysed for patients undergoing RA-TKA. A cruciate retaining cemented design was implanted using the MAKO® robotic system. Lower limb alignment at 0°, 30°, 45°, 60° and 90° of flexion was recorded at the beginning of surgery and finally after implantation of the components. A ligament tensioner was inserted after tibial precut to measure the extension and flexion gap, and final component placement was planned based on 3D CT images. Femoral and tibial component placement was measured in all three planes. A total of 104 patients were included (mean age 69.4 ± 9 years; 44 male, 60 female). The difference in component placement after planning and final implantation showed less valgus of 0.7° ± 1.4° (p < 0.001), less external rotation of 0.6° ± 1.9° (p = 0.001) and less flexion of 0.9° ± 1.8° (p < 0.001) for the femoral component. The tibial component was placed in more varus of 0.2° ± 0.9° (p = 0.056) and more posterior slope of 0.5° ± 0.9° (p < 0.001). The lower limb alignment in extension was 4.4° ± 5.2° of varus of the native knee and changed to 1.2° ± 1.9° of varus after TKA (p < 0.01). Robotic-assisted TKA helps to achieve the target of alignment and component placement very close to the planning. It allows optimal component placement of off-the-shelf implants respecting patient's specific anatomy. Level II.

Relationship between femoral component placement and patient-specific anatomical rotational landmarks in robotic arm assisted total knee Arthroplasty- a multicentric study

IntroductionOsteoarthritis of the knee is a common problem in the elderly, leading to severe morbidity. Total Knee Arthroplasty (TKA) is a widely validated surgery to provide a remarkable extent of knee function and simultaneously alleviates pain for knee osteoarthritis (OA). It is clearly understood that precision of the rotational alignment and accuracy of the technique in the placement of the femoral component is a prerequisite for excellent and successful outcomes of TKA. Advanced technology has now allowed surgeons to understand patient-specific variabilities in anatomical reference landmarks and the relationship of component positioning in relation to the reference landmarks to achieve accurate gap balancing with minimal soft tissue release.14 Robotic Arm Assisted-Total Knee Arthroplasty (RAA-TKA) is a semi-automated system that enables us in replicating the same. Using this technology, the bony resections, component positions, probable component sizing and gap balancing can be tentatively planned preoperatively with CT Scan Analysis and executed intraoperatively. Hence this study was undertaken to estimate the relationship between femoral component placement to normal rotational landmarks such as the Posterior Condylar Axis (PCA) and to quantitatively evaluate coronal and sagittal plane correction obtained. Also, we aimed to use the data to detect any anatomical variations in the study population and evaluate the accuracy of predicted component sizing, including gender-based evaluation. Materials and methodsA Prospective Observational Study of 1073 knees of patients of either sex above 50 years of age with Kellgren Lawrence Grade 4 Osteoarthritis of the knee which were confirmed with X-Ray undergoing RAA-TKA using MAKO Robotic System using Stryker Triathlon (Cruciate Substituting) CS Knee was conducted during the period between 2022 and 2023 in two South Indian hospitals specializing in joint replacement surgeries. ResultsWe found a statistically significant difference between the native Posterior Condylar Axis (PCA) (4.82 ± 2.15°) and final femoral component external rotation (3.24 ± 1.29°) with a p-value of <0.001 at 95% confidence interval. The accuracy of component size prediction was 99.8%. Also, analysis in our study has shown the most common implant sizes to be 4 in males and 2 in females. We also found no statistically significant difference based on age, size, laterality, or primary varus deformity. ConclusionsRAA-TKA provides patient-specific alignment/restricted kinematic alignment which might further enhance the outcome for the patient. Reliable deformity correction in coronal and sagittal planes can be achieved. Accurate flexion and extension gap balancing can be done through component placement and with minimal soft tissue dissection. Irrespective of all the advantages noted in RAA-TKA, further follow-up and long-term outcome studies are required to properly gauge and analyze this new technology.

Accuracy and outcome of a handheld accelerometer-based navigation device compared to conventional alignment method in total knee arthroplasty in a Chinese population

Background Total knee arthroplasty (TKA) is a successful procedure in treatment of degenerative disease of the knee, and optimal component placement is essential for long-term implant survival. The purpose of this study was to compare the accuracy of the accelerometer-based KneeAlign 2 (KA2) navigation system against conventional methods for accurate positioning of the femoral and tibial components in TKA in a Chinese population. Methods A total of 123 (37 conventional and 86 KA2) cases of elective primary TKA were reviewed. Hip-knee-ankle (HKA) angle, mechanical lateral distal femoral angle (mLDFA), and anatomical lateral distal femoral angle (aLDFA) were measured from hip-to-ankle EOS radiographs. Accuracy of conventional alignment and KA2 navigation system was assessed by measuring the difference between intraoperative goal and postoperative radiographic measurements of the components for each respective case. Results There was no significant difference between conventional alignment methods and KA2 navigation in achieving a neutral mechanical alignment of the lower limb. KA2 navigation was significantly more accurate than conventional alignment methods for optimal positioning of the tibial component in both the coronal and sagittal plane, while no significant difference between the two groups was appreciated in the positioning of the femoral component in the coronal plane. Conclusions TKA using the accelerometer-based KA2 system was found to offer a high degree of accuracy in component alignment, and in particular, significantly improved tibial component alignment in comparison with conventional alignment methods in a Chinese population. However, no significant improvements were observed in neutral mechanical axis of the lower limb alignment and femoral component placement in the coronal plane.

Intraoperative changes in medial joint gap after posterior femoral condylar resection, posterior osteophyte removal, and femoral component placement during primary total knee arthroplasty

Background“Mid-flexion stability” is important for superior patient satisfaction following total knee arthroplasty (TKA). Thus, it is important to control medial joint gap intraoperatively as a countermeasure. However, reports on the precise intraoperative changes in medial joint gap during TKA are scarce. This study evaluated the intraoperative changes in medial joint gap during TKA. MethodsWe studied 167 knees with varus osteoarthritis that underwent 80 cruciate-retaining (CR) and 87 posterior-stabilized (PS) TKAs between January 2018 and December 2020. We measured the intraoperative changes in medial joint gap with a tensor device at 137.5 N. ResultsThe medial joint gap after posterior femoral condylar resection was significantly increased not only at 90° of flexion but also at 0° of extension in CR and PS TKAs (p < 0.01). The medial joint gap after posterior osteophyte removal was significantly increased not only at 0° of extension but also at 90° of flexion in CR and PS TKAs (p < 0.01). The medial joint gap at 0° of extension was reduced by 0.60 mm after femoral component placement in PS TKA. ConclusionSurgeons need to pay close attention to these intraoperative changes in medial joint gap by measuring the medial joint gap before and after each procedure or assuming the changes in those values before bone cutting to achieve superior patient satisfaction following TKA.

The Effect of Prosthesis Type on Intraoperative Soft-Tissue Balance and Clinical Outcomes in Modified Kinematically Aligned Cruciate-Retaining Total Knee Arthroplasty.

Kinematically aligned total knee arthroplasty (KA-TKA) has gained interest for achieving more favorable clinical outcomes than mechanically aligned TKA. One of the advantages of KA-TKA is reported to be an easy acquisition of intraoperative soft-tissue balance without excessive medial release for varus osteoarthritis. However, we hypothesized that the prosthesis type affects intraoperative soft-tissue balance even in the KA-TKA. The present study aimed to compare intraoperative soft-tissue balance and clinical outcomes of KA-TKAs using single-radius (SR) or multiradius (MR) prostheses. AND METHODS: Consecutive 70 cruciate-retaining modified KA-TKAs (31 SR and 39 MR) were performed in patients with varus-type osteoarthritis using a navigation system. Intraoperative soft-tissue balance including joint component gap and varus/valgus balance was measured with femoral component placement and patellofemoral joint reduction throughout the range of motion using offset-type tensor and compared between the two groups. Two years postoperatively, the range of motion and 2011 Knee Society Scores were compared between the two groups. Joint component gaps showed no significant differences between the two groups from 0 to 30 degrees of flexion. However, during 60 to 120 degrees of flexion, joint component gaps of SR group showed significantly larger values than those of MR group (p < 0.05). There were no significant differences in varus/valgus balance throughout the range of motion between the two groups. The postoperative clinical outcomes showed no significant differences between the two groups. Despite no difference in clinical outcomes, joint component gap showed different patterns due to the prosthesis type in modified KA-TKAs.

Post operative correlation of femoral tibial components with knee alignment using roentgenographic index in patients undergoing total knee arthroplasty in a tertiary referral centre

Total knee arthroplasty is the leading surgical treatment for advanced osteoarthritis of the knee. Despite its efficiency, approximately twenty percent of the cases are dissatisfied with the outcome. Mal positioning of components results in loosening, which has long-term consequences. As a result, proper sizing and placement are important for optimal functional and long-term outcomes. Achieving limb alignment, good soft tissue balance and pain relief are the primary goals of the surgeon upon completion of total knee replacement (TKA). The aim of this study was to determine the accuracy of placement of femoral and tibial components post-operatively in relation to knee alignment using a roentgenographic index. This is a prospective study conducted in a tertiary care referral hospital, we included a total of fifty cases who underwent total knee arthroplasty from the year 2019 to 2020. Post-operative radiographic parameters were measured using digital software and compared using roentgenographic indexes as described by Lotke et al. Out of the fifty Total Knee Arthroplasty cases, twenty-eight knees had perfectly positioned tibial and femoral prosthesis, fifteen cases had good position of both the components. Tibial component alignment angle (β = 90°) in relation to mechanical axis in coronal plane was seventy six percent; fourteen percent of the cases were in native knee varus. Femoral component alignment angle (α) with acceptable anatomical valgus (0-7°) were more than eighty percent of the cases. 85.5 was the mean roentgenographic index which was strongly correlatable with other similar studies. With good clinical acumen and using conventional alignment system, near to normal knee alignment in total knee arthroplasty is achievable.

Direct Anterior Birmingham Hip Resurfacing: Surgical Technique

Birmingham hip resurfacing (BHR) arthroplasty is an established alternative to total hip arthroplasty for end-stage osteoarthritis, specifically in the younger male patient population who wish to return to high-performance physical activity. Traditionally, this procedure has been performed via the posterolateral approach mainly due to the design of intraoperative equipment utilized for femoral component placement. In other words, no current intraoperative equipment has been designed to perform the BHR via any approach other than the posterolateral approach. Recent literature has shown numerous advantages to direct anterior approach arthroplasty, among total hip arthroplasty patients, such as shorter recovery times, less pain, and improved overall functional outcomes. This technique paper aims to highlight a step-by-step approach of achieving the benefits of direct anterior approach arthroplasty in the patients indicated for BHR. A novel guide-pin technique has been developed to account for lack of intraoperative equipment, with pearls and pitfalls explained in detail. We hope this technique will help to guide surgeons in performing the direct anterior BHR with safety and success thereby maximizing patient outcomes.

The posterior cortical axis as an alternative reference for femoral component placement in total knee arthroplasty

BackgroundAlthough several reference axes have been established for determining femoral rotational alignment during total knee arthroplasty (TKA), the most accurate axis is undetermined. This study determines the relationship between the posterior cortical axis (PCA) and the trochlear anterior line (TAL) of the femur in relation to the epicondylar axis.MethodsA total of 341 patients who underwent TKA for osteoarthritis were enrolled. Patients who had undergone previous bony surgery or replacement that might have changed the femoral geometry were excluded. Finally, 336 patients (200 females and 136 males) were included in the study. The angles between the transepicondylar axis (TEA) and TAL and TEA and the femoral PCA (FPCA) were evaluated. We also assessed whether there was any significant differences in variance and gender in these two angles. Student’s t tests were used to determine the significance of coronal alignment and any gender-based differences. The variances between the TAL/TEA and FPCA/TEA angles were compared using F tests.ResultsThe FPCA was externally rotated by 2.6° ± 3.6°, and the trochlear anterior line was internally rotated by 5.2° ± 5.5°, relative to the TEA. Gender-based differences were observed in the comparisons between anatomical references and TEA.ConclusionsThe FPCA is a more conservative landmark than the TAL for intraoperative or postoperative approximation of the TEA. When conventional reference axes, such as the posterior condylar axis and the anteroposterior axis, are inaccurate, surgeons can refer to this alternative reference. These findings demonstrate that the FPCA may be useful for determining the rotational alignment of the femoral component before and during TKA.

Validity of intraoperative imageless navigation (Naviswiss) for component positioning accuracy in primary total hip arthroplasty: protocol for a prospective observational cohort study in a single-surgeon practice

IntroductionOptimal outcomes in total hip arthroplasty (THA) are dependent on appropriate placement of femoral and acetabular components, with technological advances providing a platform for guiding component placement to reduce the...

Low pelvic incidence is a risk factor for intraoperative complications in minimally invasive anterolateral approach for total hip arthroplasty.

Minimally invasive anterolateral approach (ALA) has gained popularity in recent years as better postoperative functional recovery and lower risk of postoperative dislocation are claimed. However, difficulties for femur exposure and intraoperative complications during femoral canal preparation and component placement have been reported. This study analyses the effect of anatomical factors on difficulties for femoral access and intraoperative complications with a modified minimally invasive ALA. 310 consecutive patients who had primary unilateral total hip arthroplasty (THA) by single surgeon using same approach and technique, and being suitable for EOS were included. All patients underwent pre- and postoperative standing and sitting full-body EOS acquisitions and pelvic and femoral parameters were measured. All intra- and postoperative complications for femoral preparation and implantation were assessed. Intraoperative complications included femoral fractures and difficulties for femoral exposure. 10 patients (3.2%) had intraoperative femoral fractures (2 greater trochanter, 8 calcar). Difficult access to the proximal femur was reported for 10 other patients (3.2%). Patients with intraoperative complications presented a significantly lower pelvic incidence (PI) than patients without intraoperative complications (mean PI: 39.4° vs. 56.9°, p < 0.001). The pelvic incidence can be useful to detect anatomically less favourable patients for THA implantation using ALA.

Intra- and postoperative assessment of femoral component rotation in total knee arthroplasty: an EKA knee expert group clinical review.

Malrotation of the femoral component after primary total knee arthroplasty (TKA) is one of the most important problems leading to painful TKA requiring revision surgery. A comprehensive systematic review of the literature was performed to present current evidence on how to optimally place the femoral component in TKA. Several landmarks and techniques for intraoperative determination of femoral component placement and examination of their reliability were analyzed. 2806 articles were identified and 21 met the inclusion criteria. As there is no unquestioned gold standard, numerous approaches are possible which come along with specific advantages and disadvantages. In addition, imaging modalities and measurements regarding postoperative femoral component rotation were also investigated. Femoral component rotation measurements on three-dimensional (3D) reconstructed computerised tomography (CT) images displayed intraclass correlation coefficients (ICC) above 0.85, significantly better than those performed in radiographics or two-dimensional (2D) CT images. Thus, 3D CT images to accurately evaluate the femoral prosthetic component rotation are recommended, especially in unsatisfied patients after TKA. The EKA Femoral Rotation Focus Group has not identified a single best reference method to determine femoral component rotation, but surgeons mostly prefer the measured resection technique using at least two landmarks for cross-checking the rotation. III.

Comparison of intraoperative soft tissue balance measurement between two tensor systems in total knee arthroplasty

BackgroundDifferences in measurement outcomes using different tensors in total knee arthroplasty (TKA) remain unknown. This study aimed to compare intraoperative soft tissue balance between two measurement systems in TKA. MethodsThis study included 24 cruciate-retaining (CR) and 27 posterior-stabilized (PS) TKAs for varus-type osteoarthritis. All TKAs were performed with the measured resection technique. Intraoperative soft tissue balance was assessed with femoral component placement and patellofemoral joint reduction throughout the range of motion. Measurements were performed using the Offset Repo-Tensor (Zimmer) and Ligament Sensor Tensor (Depuy). Joint component gaps and varus/valgus ligament balance were compared statistically in CR and PS TKAs. ResultsJoint component gaps with the Offset Repo-Tensor were significantly larger at 0°, 10°, 30°, and 60° of knee flexion in CR TKA and at all knee flexion angles, except 0° and 135°, in PS TKA than those with the Ligament Sensor Tensor (P < .05). Varus balance with the Offset Repo-Tensor was significantly larger at 0°, 10°, and 30° of knee flexion in CR TKA and at 10°, 30°, 60°, 90°, and 120° of knee flexion in PS TKA than that with the Ligament Sensor Tensor (P < .05). ConclusionSurgeons should consider the discrepancy in assessing intraoperative soft tissue balance depending on the tensor used. The Ligament Sensor Tensor tended to underestimate soft tissue balance in CR and PS TKAs compared with the Offset Repo-Tensor, especially in PS TKA. Thus, surgeons should know the difference in values between the offset-type tensor with consistent distraction force and a spring-loaded tensor.

Enhanced conventional method is as precise as navigation for distal femur resection during total knee replacement: a randomized controlled trial

Introduction: The purpose of this prospective study was to determine the accuracy of distal femoral cut and femoral component placement in the coronal plane with the enhanced conventional technique when compared to computer navigation during total knee replacement (TKR). Methods: In total, 475 total knee arthroplasties (TKA) were analyzed (200 optimized conventional TKAs and 275 navigated TKAs) for postoperative mechanical alignment or hip-knee-ankle angle and femoral component coronal alignment and compared between the two groups Results: Mean femoral component coronal alignment was not significantly different (p=0.35) when navigation and enhanced conventional groups were compared. There was no significant difference in the mean femoral component coronal alignment between knees with a valgus correction angle (VCA) &lt;5° (p=0.28), knees with VCA 5°-7° (p=0.48) and knees with &gt;7° (p=0.09). No significant difference was noted in the mean femoral component coronal alignment between knees with varus deformity &lt;10° (p=0.19), varus deformity 10°-20° (p=0.72) and valgus deformity (p=0.35). Conclusions: Using the enhanced conventional technique in each patient to perform distal femoral cut during total knee arthroplasty can help achieve the coronal alignment of the femoral component comparable to navigation technique. Registration: UMIN-CTR ID UMIN000036204.

Effects of femoral component placement on the balancing of a total knee at surgery

Misalignment and soft-tissue imbalance in total knee arthroplasty (TKA) can cause discomfort, pain, inadequate motion and instability that may require revision surgery. Balancing can be defined as equal collateral ligament tensions or equal medial and lateral compartmental forces during the flexion range. Our goal was to study the effects on balancing of linear femoral component misplacements (proximal, distal, anterior, posterior); and different component rotations in mechanical alignment compared to kinematic alignment throughout the flexion path. A test rig was constructed such that the position of a standard femoral component could be adjusted to simulate the linear and rotational positions. With the knee in neutral reference values of the collateral tensions were adjusted to give anatomic contact force patterns, measured with an instrumented tibial trial. The deviations in the forces for each femoral component position were then determined. Compartmental forces were significantly influenced by 2 mm linear errors in the femoral component placement. However, the errors were least for a distal error, equivalent to undercutting the distal femur. The largest errors mainly increase the lateral condyle force, occurred for proximal and posterior component errors. There were only small contact force differences between kinematic and mechanical alignment. Based on these results, surgeons should avoid overcutting the distal femur and undercutting the posterior femur. However, the 2–3 degrees varus slope of the joint line as in kinematic alignment did not have much effect on balancing, so mechanical or kinematic alignment were equivalent.

Improvement of the Gap Adjustment in Total Knee Arthroplasty Using the Posterior Condylar Pre-cut Technique.

To provide adequate gaps for knee extension and flexion during total knee arthroplasty, a femoral component placement decreases the extension gap because the posterior capsule tension increases against the protrusion of the posterior part of the femoral component. We thought that the influence of this component on the extension gap depends on the amount of posterior femoral bone resection and the thickness of the posterior femoral components. We hypothesized that less bone resection and a thinner posterior part of the femoral component might avoid these problems. To verify our hypothesis, a 4-mm posterior condylar pre-cut technique and temporary femoral components that were 8 and 4 mm thick in the distal and posterior parts, respectively, were made using the FINE Total Knee System (Teijin-Nakashima Medical Co., Okayama, Japan). After bone resection, the pre-cut trial component was set to the femur, and the bone and component setting gaps were estimated. Seventy-one patients (98 knees) were investigated. The average bone gaps were 17.2/15.0 mm (extension/flexion, after pre-cut), 18.3/16.3 mm (after soft tissue release), and 8.7/12.2 mm (after pre-cut trial setting). After pre-cut trial setting, the extension gap decreased significantly; the amount was 1.6 mm (0-4 mm) on average (p < 0.0001), whereas a change of 3 mm or more occurred in 15 knees (15.3%), which could be problematic. The degree of these changes after component setting could be reduced by using the posterior femoral condylar pre-cut technique. However, the problem of component setting on the extension gap was not completely resolved. To precisely project the intraoperative gap to the ultimate postoperative gap, a posterior small protrusion device such as a pre-cut trial with the pre-cut technique would be necessary.

No correlation between rotation of femoral components in the transverse plane and clinical outcome after total knee arthroplasty.

It was hypothesized that malrotation of femoral component in total knee arthroplasty (TKA) will significantly impact clinical outcome. Eighty-eight consecutive patients with primary osteoarthritis of the knee were prospectively evaluated. They received a cemented posterior stabilized TKA (NexGen, Zimmer/Biomet® Inc., Warsaw, IN, USA). The femoral component was placed in 3° of external rotation referenced to the posterior condylar line. Postoperatively, a CT scan was performed to evaluate rotation of femoral component in the transverse plane. SF-36, KSS, and WOMAC, as well as their range of motion was assessed prior to surgery, after 6 and 24months. Data are presented as mean and standard deviation (SD), as well as range if applicable. Correlation analysis was performed between the placement of the femoral component in the transverse plane and the clinical outcome. Femoral component placement was on average 0.1° [SD 2.5°, range - 6.5° to + 6.5°] referenced to the surgical transepicondylar line showing a wide range between the two landmarks after surgery. After 6months, WOMAC category 'physical function' correlated significantly with femoral component rotation (r = - 0.28, p = 0.007). After 24months, WOMAC categories 'physical function' and 'pain' correlated significantly with femoral rotation (r = - 0.41, p < 0.001; and r = - 0.33, p = 0.001). No significant correlations were found between femoral component rotation and range of motion (r = 0.04), WOMAC category "stiffness", KSS, as well as SF-36 questionnaires. These reported formally significant correlations were without any clinical relevance. The study showed that there is a significant patients specific femoral component placement in the transverse plane. Internal or external malrotation of the femoral component does not correlate automatically with poor knee function. The lack of correlation between femoral component position and clinical as well as functional outcome underlines complexity and significant individuality of each patient. The surgeon should be aware of the finding and attention should be paid during surgery when significant divergency is seen between the two landmarks. Soft tissue balancing might be very crucial in these specific patients, which needs to be studied in depth in the future. II.

Morphometric evaluation of acetabular dimensions: A computed tomography-based study from a tertiary care center in rural North-West India

Introduction: The success of total hip replacement depends on the ideal placement of both acetabular and femoral component, so having a complete awareness regarding acetabular parameters including its morphology is an important requirement for successful surgery. Materials and Methods: A hospital-based observational study was conducted on all patients in the age group of 18 years, and above submitting to the Department of Radiodiagnosis for either abdominal, lower spinal, or nonorthopedic pathology of pelvic and hip region were included in this study. Acetabular dimensions (acetabular depth [Ac.D] and acetabular width [Ac.W]) were evaluated with the help of digital scale of computed tomography console room monitor. Results: The findings from the current study show that the Ac.D and Ac.W in the study population was 14.6 and 50.2 mm, respectively. The study shows no side-to-side difference in values. However, it was observed that values were larger in men as compared to women in the study population. Conclusions: There is a need to develop templates for arthroplasty which are sex specific and not universal.

Posterior condylar offset influences the intraoperative soft tissue balance during posterior-stabilized total knee arthroplasty.

This study aimed to clarify the influence of the posterior condylar offset (PCO) on intraoperative soft tissue balance including the joint component gap and varus ligament balance measured by an offset-type tensor during posterior-stabilized (PS) total knee arthroplasty (TKA). In this study, 35 patients with osteoarthritis of the knee underwent PS TKA. Intraoperative soft tissue balance including the joint component gap and varus/valgus ligament balance were assessed at 0°, 10°, 45°, 90°, and 135° of flexion with an offset-type tensor that could be used with the femoral component placement and patellofemoral joint reduction. The correlations between the postoperative PCO and the intraoperative soft tissue balance parameters were assessed using simple regression analysis. The joint component gap at 0° extension was inversely correlated with the PCO (R=-0.41, p<0.05). The joint component gap of 10°-0° was positively correlated with the PCO (R=0.35, p<0.05). No other soft tissue balance parameters were correlated with the PCO. A larger PCO was confirmed to reduce joint component gap in extension but not always in flexion in PS TKA.

Relatively Loose Flexion Gap Improves Patient-Reported Clinical Scores in Cruciate-Retaining Total Knee Arthroplasty.

Although appropriate soft tissue balancing is well recognized as essential procedure in total knee arthroplasty (TKA), poor relationship between intraoperative soft tissue balance and physician-reported clinical outcomes was reported. Since physician-derived scores are reported to be poorly related to patient-reported scores, patient-derived outcome scales have received a great deal of attention and have become increasingly important. Thus, it should be clarified whether intraoperative soft tissue balance influences patient-reported clinical outcomes. Therefore, the purpose of this study was to investigate the relationship between intraoperative soft tissue balance and patient-reported clinical outcomes in TKA. A total of 35 TKAs were performed in patients with varus-type osteoarthritis, using the tibia first technique with a navigation system. Soft tissue balance (joint component gap and varus/valgus ligament balance) with femoral component placement and temporarily repaired patellofemoral joint were intraoperatively assessed with an offset-type tensor under 40 lb of joint distraction force. Measurements were performed at 0, 10, 30, 60, 90, and 120 degrees of knee flexion. Subjective clinical outcomes were assessed using the 2011 Knee Society score, which consists of objective knee indicators, patient satisfaction, patient expectations, and functional activities at the minimum 1-year follow-up. The relationship between each parameter in soft tissue balance and subjection clinical score was assessed using a simple linear regression model. Objective knee indicators, especially patient-reported symptoms, showed positive correlations with joint component gap difference of 90 to 0 and 120 to 0 degrees. Patient satisfaction and expectations also exhibited positive correlations with joint component gap difference of 90 to 0 and 120 to 0 degrees. There were no correlations among any parameters of soft tissue balance and functional activities. The other parameters, including varus/valgus ligament balance, showed no statistical correlations with clinical scores. In conclusion, intraoperative soft tissue balance influenced the postoperative clinical outcomes, where a relatively loose flexion gap resulted in higher scores for the parameters of pain, patient satisfaction, and patient expectations.