Medial ball and socket total knee arthroplasty

Abstract

Aims Between 15% and 20% of patients remain dissatisfied following total knee arthroplasty (TKA). The SAIPH knee system (MatOrtho, Surrey, United Kingdom) is a medial ball and socket TKA that has been designed to replicate native knee kinematics in order to maximize the range of movement, stability, and function. This system is being progressively introduced in a stepwise fashion, with this study reporting the mid-term clinical and radiological outcomes. Patients and Methods A retrospective review was undertaken of the first 100 consecutive patients with five-year follow-up following SAIPH TKA performed by the senior authors. The data that were collected included the demographics of the patients, clinical findings, the rate of intraoperative ligamentous release, patient-reported outcome measures (PROMS), radiological assessment, complications, and all-cause revision. Revision data were cross-checked with a national registry. Results A total of 100 TKAs in 92 patients were included. Three patients died (three TKAs) and a further two TKAs were revised. Of the remaining 95 TKAs, five-year follow-up data were available for 81 TKAs (85%) in 87 patients. There were significant improvements in all PROMs and high satisfaction. The mean ROM at final follow-up was from 0° (full extension) to 124° flexion. There were seven major complications (7%): one infection, two deep vein thromboses, one cerebrovascular event, and two patients with stiffness requiring a manipulation under anaesthesia. Two patients required a lateral retinacular release to optimize patellar tracking in valgus knees; no additional ligament releases were performed in any patient. Radiological analysis demonstrated no evidence of implant-related complications. Conclusion These results demonstrate satisfactory clinical and radiological outcomes at five years following a medial ball and socket TKA. The complication and revision rates are consistent with those previously reported for patients undergoing TKA. These results demonstrate the safety and efficacy of the SAIPH Knee TKA system and support its wider use.

Total knee arthroplasty using modified measured resection: a five-year retrospective review of midterm outcomes

“…Diduch et al reported: late infection (two out of 103 knee joints, or 2%); polyethylene thinning and instability requiring change of the tibial component (one case each, or 1% each); and tibial component dislocation (three cases, or 3%) [24]. Katchky found seven major complications (7%) in patients with SAIPH TKA: one infection, two deep vein thromboses, one cerebrovascular event, and two patients with stiffness requiring manipulation under anaesthesia [31]. Wilson noted a significantly higher number of venous thromboembolic events and major cardiac events after TKA following unicom- Figure 2.…”

“…According to the literature, excellent and good outcomes account for 90-98% of cases in the follow-up period of three to 14 years [24][25][26][27][28][29][30][31], depending on the type of prosthesis and on the surgical technique. Thus, the results of this retrospective research are similar to those published by other authors, indicating the effectiveness of modified measured resection in cemented total knee arthroplasty performed with the PFC Total Knee System (Table II).…”

“…The functional status assessment is subjective and affects patient satisfaction after TKA. Thus, Katchky indicate that despite generally good outcomes after TKA, between 15% and 20% of patients remain dissatisfied [31]. This number decreases over time as patients adapt to their knee systems [47] ( Table III).…”

“…The literature on similar operations does not provide a universal standard for a follow-up period. Follow-up periods of 3 to 14 years [24][25][26][27][28] and 5 to 6 years are often used [29][30][31]. This study used a period from five years because it is enough time for adaptation to a new knee system and lifestyle, which provokes an objective assessment of outcomes.…”

Sagittal Stability and Implant Design Affect Patient Reported Outcomes After Total Knee Arthroplasty

“…The CR knees used by surgeons in this study are proven to demonstrate low cumulative percent revision on the Australian Orthopaedic Association National Joint Replacement Registry. The MS TKA examined in this study uses a "ball-and-socket" design philosophy with a spherical medial femoral condyle (the "ball") articulating with a highly congruent spherical polyethylene bearing surface (the "socket") with 5-year results recently reported [3]. This arrangement facilitates near-perfect conformity across the bearing surface that maximizes the contact surface area (spherical-contact) and eliminates both point loading and sliding motion because of shear forces across the bearing surface (Fig.…”