Medial Ball and Socket Total Knee Arthroplasty in Indian Population: 5-Year Clinical Results

PCL retention demonstrates better functional scores and gait patterns in total knee arthroplasty using a medial congruent insert-a prospective study

PURPOSE

Despite Total Knee Arthroplasty (TKA) being one of the most successful procedures for end stage arthritis, nearly 20% of patients undergoing this procedure remain dissatisfied. Various design options have been introduced to reduce this cohort of patients. One such option has been the introduction of the medial congruent (MC) polyethylene design. This study was undertaken to evaluate outcome measures and gait analysis in patients undergoing bilateral single stage TKA where the posterior cruciate ligament (PCL) was retained or excised in contralateral knees.

METHODS

60 bilateral TKA's were performed by a single surgeon using a MC design option from July to Sep 2021. The study lots included patients between the ages of 55 and 70 years with fixed varus deformity of degenerative aetiology, and Kellgren Lawrence Grade 3 and 4 radiological changes. Exclusion criteria were previous surgery to the lower extremities, sero positive arthropathies, post traumatic arthritis, valgus deformity, flexion contractures > 20°, and any pre-existing pathology impacting gait, e.g., poliomyelitis, or neuromuscular disorders. The PCL was retained or sacrificed on contralateral sides for the purpose of this study. Functional scores, outcomes and gait analysis on level and gradient walking were evaluated at a follow-up of 18 months.

RESULTS

At 18, months the Range of Motion (ROM) improved from a preoperative value of 97.3 ± 11.5 to 110.3 ± 6.1 on the PCL retained side (MC-PCL) and from 96.5 ± 10.8 to 113 ± 5.8 on the PCL excised side (MC-PCLX). Knee Society Score (KSS-2011) improved from a preoperative value of 21.2 ± 4.5 to 89.8 ± 3.4 at 18 months postoperatively on the MC-PCL side and from 21.5 ± 4 to 88.2 ± 3.7 on the MC-PCLX side. Forgotten Joint Score (FJS-12) was 8.8 ± 0.7 on the MC-PCL side and 8.1 ± 0.9 on the MC-PCLX side 18 months after surgery. Our gait analysis evaluation demonstrated a lower forefoot pressure in the MC-PCL group in comparison to the MC-PCLX group when subjects were made to walk on a 30° upward incline. This difference was found to be statistically significant.

CONCLUSION

In this study, while ROM was greater in the MC-PCLX study lot, patient satisfaction was higher in the MC-PCL study lot. Gait assessment demonstrated lower forefoot pressure while ascending an incline of 30° in the MC-PCL study lot as compared to the MC-PCLX study lot approximating normal gait patterns.

LEVEL OF EVIDENCE

II.

Early Results of Bone-Conserving High Flexion Posterior-Stabilized Total Knee System in Indian Population

Background

A number of total knee arthroplasty (TKA) systems are used across a variety of markets in which outcome will be influenced by patient factors, surgical technique and implant characteristics. The aim of the current study was to report the early functional results of a primary TKA system in support of the component design characteristics adapted for achieving increased functional expectations of the patients.

Materials and Methods

A prospective, continuous series of 304 primary posterior-stabilized (PS) TKAs were performed in 208 patients by a single surgeon. Inclusion criterion was patients undergoing primary TKA with Freedom Total Knee system and willing to participate in the study. Exclusion criteria were patients undergoing revision TKA, patients not willing to participate and patients who were lost to follow-up. Patients were clinically and radiologically assessed for a minimum of 5 years post-operatively. Oxford Knee score (OKS) and range of motion (ROM) were assessed for the entire study population and by gender.

Results

There were no patients who were lost to follow-up. Two patients (Two knees) required incision and secondary suturing for superficial skin wound complication. At minimum 5-year follow-up, there was no radiographic evidence of component loosening/failure. Clinical evaluation at 5 years post-operatively showed statistically significant increase in the OKS and ROM as compared to pre-operative values (OKS pre-operative 19.27 ± 1.86, post-operative 38.76 ± 1.5, p value < 0.001, ROM pre-operative 94.57 ± 3.49, post-operative 127.69 ± 3.65, p value < 0.001). There was no statistically significant difference in the clinical outcome between male and female genders as well as between unilateral and bilateral TKA.

Conclusion

The study showed encouraging early results for the bone-conserving high flexion TKA system in 208 patients at minimum 5-year follow-up. The adapted design characteristics for improved functional expectations are confirmed in this reported Indian population study group cohort. Further continued evaluation is warranted for this primary TKA system across Indian and other ethnic population.

Comparison of Anatomical Conformity between TomoFix Anatomical Plate and TomoFix Conventional Plate in Open-Wedge High Tibial Osteotomy

Background and Objectives: The TomoFix anatomical plate was developed to improve plate position, proximal screw direction, and post-correction tibial contouring. The purpose of this study was to compare postoperative configurations between the TomoFix anatomical plate and the TomoFix conventional plate. It was hypothesized that the new modified plate provides a better fixative coaptation than the conventional plate. Materials and Methods: A total of 116 cases (112 patients) were enrolled in this study from March 2015 to February 2021. Among them, 63 patients underwent surgery using the TomoFix conventional plate, and 53 underwent surgery using the TomoFix anatomical plate. The radiographic outcomes, including the hip−knee−ankle (HKA) angle, medial proximal tibial angle (MPTA), tibial slope, plate angle, proximal screw angles, and plate-to-cortex distance at #1 hole (just below the osteotomy site) were compared between the two groups. Results: Patients with the TomoFix anatomical plate showed similar results in terms of the pre- and postoperative HKA angle, MPTA, and tibial slope. The TomoFix anatomical group showed a significantly greater plate angle (39.2° ± 8.1° vs. 31.7° ± 7.0°, p < 0.001) and less screw angles, indicating that the TomoFix anatomical plates allowed a more posterior plate position than the conventional plate. The plate-to-cortex distance was significantly less in the TomoFix anatomical group than in the TomoFix conventional group (p < 0.001). Conclusion: The TomoFix anatomical plate showed a more posteromedial plating position, better proximal screw direction to the lateral hinge, and improved post-correction tibial contour compared to the TomoFix conventional plate.