Advertisement for orthosearch.org.uk
Results 1 - 8 of 8
Results per page:
Bone & Joint Research
Vol. 11, Issue 2 | Pages 91 - 101
1 Feb 2022
Munford MJ Stoddart JC Liddle AD Cobb JP Jeffers JRT

Aims

Unicompartmental and total knee arthroplasty (UKA and TKA) are successful treatments for osteoarthritis, but the solid metal implants disrupt the natural distribution of stress and strain which can lead to bone loss over time. This generates problems if the implant needs to be revised. This study investigates whether titanium lattice UKA and TKA implants can maintain natural load transfer in the proximal tibia.

Methods

In a cadaveric model, UKA and TKA procedures were performed on eight fresh-frozen knee specimens, using conventional (solid) and titanium lattice tibial implants. Stress at the bone-implant interfaces were measured and compared to the native knee.


The Bone & Joint Journal
Vol. 101-B, Issue 7_Supple_C | Pages 40 - 47
1 Jul 2019
Sporer S MacLean L Burger A Moric M

Aims

Our intention was to investigate if the highly porous biological fixation surfaces of a new 3D-printed total knee arthroplasty (TKA) achieved adequate fixation of the tibial and patellar components to the underlying bone.

Patients and Methods

A total of 29 patients undergoing primary TKA consented to participate in this prospective cohort study. All patients received a highly porous tibial baseplate and metal-backed patella. Patient-reported outcomes measures were recorded and implant migration was assessed using radiostereometric analysis.


The Bone & Joint Journal
Vol. 103-B, Issue 6 Supple A | Pages 32 - 37
1 Jun 2021
Restrepo S Smith EB Hozack WJ

Aims. Cementless total knee arthroplasty (TKA) offers the potential for strong biological fixation compared with cemented TKA where fixation is achieved by the mechanical integration of the cement. Few mid-term results are available for newer cementless TKA designs, which have used additive manufacturing (3D printing). The aim of this study was to present mid-term clinical outcomes and implant survivorship of the cementless Stryker Triathlon Tritanium TKA. Methods. This was a single institution registry review of prospectively gathered data from 341 cementless Triathlon Tritanium TKAs at four to 6.8 years follow-up. Outcomes were determined by comparing pre- and postoperative Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) scores, and pre- and postoperative 12-item Veterans RAND/Short Form Health Survey (VR/SF-12) scores. Aseptic loosening and revision for any reason were the endpoints which were used to determine survivorship at five years. Results. At mid-term follow-up, the mean KOOS JR score improved significantly from 33.14 (0 t0 85, standard deviation (SD) 21.88) preoperatively to 84.12 (15.94 to 100, SD 20.51) postoperatively (p < 0.001), the mean VR/SF-12 scores improved significantly from physical health (PH), 31.21 (SD 5.32; 23.99 to 56.77) preoperatively to 42.62 (SD 10.72; 19.38 to 56.82) postoperatively (p < 0.001) and the mental health (MH), 38.15 (SD 8.17; 19.06 to 60.75) preoperatively to 55.09 (SD 9.64; 19.06 to 66.98) postoperatively (p < 0.001). A total of 11 revisions were undertaken, with an overall revision rate of 2.94%, including five for periprosthetic joint infection (1.34%), three for loosening (0.80%), two for instability (0.53%), and one for pain (0.27%). The overall survivorship was 97.06% and survivorship for aseptic loosening as the endpoint was 98.40%, with a 99.5% survivorship of the 3D-printed tibial component. Conclusion. This 3D-printed cementless total knee system shows excellent survivorship at mid-term follow-up. This design and the ability to obtain cementless fixation offers promise for excellent long-term durability. Cite this article: Bone Joint J 2021;103-B(6 Supple A):32–37


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_9 | Pages 71 - 71
1 Oct 2020
Restrepo S Hozack WJ Smith EB
Full Access

Introduction. Cementless TKA offers the potential for strong fixation through biologic fixation technology as compared to cemented TKA where fixation is achieved through mechanical integration of the cement. Few mid-term results are available for newer cementless TKA designs that have used additive manufacturing (3-D printing) for component design. The purpose of this study is to present minimum 5-year clinical outcomes and implant survivorship of a specific cementless TKA using a novel 3-D printed tibial baseplate. Methods. This is a single institution registry review of the prospectively obtained data on 296 cementless TKA using a novel 3-D printed tibial baseplate with minimum 5-year follow-up. Outcomes were determined by comparing pre- and post-operative Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) scores and pre- and post-operative 12 item Veterans RAND/Short Form Health Survey (VR/SF-12). Aseptic loosening as well as revision for any reason were the endpoints used to determine survivorship at 5 years. Results. At minimum 5-year follow-up, the KOOS JR score improved from 34.88 pre-operatively to 84.29 post-operatively (p-values = 0.0001), the VR/SF-12 scores improved from PH − 31.98 pre-operatively to 42.80 post-operatively (p-values = 0.0001) and the MH − 37.24 pre-operatively to 55.16 post-operatively (p-value = 0.0001). Eleven revisions were performed for an overall revision rate of 2.94% - including 5 PJI (1.34%), 3 loosening (0.80%), 1 instability (0.27%), 2 pain (0.53%). The overall 5-year survivorship was 97.1% and survivorship for aseptic loosening as the endpoint was 98.40%. The survivorship of the 3-D printed porous tibial component was 99.2%. Conclusion. This 3-D printed tibial baseplate and cementless total knee system shows excellent survivorship at 5-year follow-up. The design of this implant and the ability to obtain cementless fixation offers promise for excellent long-term durability


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_9 | Pages 72 - 72
1 Oct 2020
Howard JL Williams HA Lanting BA Teeter MG
Full Access

Background. In recent years, the use of modern cementless implants in total knee arthroplasty has been increasing in popularity. These implants take advantage of new technologies such as additive manufacturing and potentially provide a promising alternative to cemented implant designs. The purpose of this study was to compare implant migration and tibiofemoral contact kinematics of a cementless primary total knee arthroplasty (TKA) implanted using either a gap balancing (GB) or measured resection (MR) surgical technique. Methods. Thirty-nine patients undergoing unilateral TKA were recruited and assigned based on surgeon referral to an arthroplasty surgeon who utilizes either a GB (n = 19) or a MR (n = 20) surgical technique. All patients received an identical fixed-bearing, cruciate-retaining beaded peri-apatite coated cementless femoral component and a pegged highly porous cementless tibial baseplate with a condylar stabilizing tibial insert. Patients underwent a baseline radiostereometric analysis (RSA) exam at two weeks post-operation, with follow-up visits at six weeks, three months, six months, and one year post-operation. Migration including maximum total point motion (MTPM) of the femoral and tibial components was calculated over time. At the one year visit patients also underwent a kinematic exam using the RSA system. Results. Mean MTPM of the tibial component at one year post-operation was not different (mean difference = 0.09 mm, p = 0.980) between the GB group (0.85 ± 0.37 mm) and the MR group (0.94 ± 0.41 mm). Femoral component MTPM at one year post-operation was also not different (mean difference = 0.27 mm, p = 0.463) between the GB group (0.62 ± 0.34 mm) and the MR group (0.89 ± 0.44 mm). Both groups displayed a lateral pivot pattern with similar frequencies of condylar separation. Conclusion. There was no difference in implant migration and kinematics of a single-radius, cruciate retaining cementless TKA performed using a GB or MR surgical technique. The magnitude of migration suggests there is no risk of early loosening. The results provide support for the use of a cementless TKA as a viable alternative to cemented fixation


The Bone & Joint Journal
Vol. 101-B, Issue 7_Supple_C | Pages 115 - 120
1 Jul 2019
Hooper J Schwarzkopf R Fernandez E Buckland A Werner J Einhorn T Walker PS

Aims

This aim of this study was to assess the feasibility of designing and introducing generic 3D-printed instrumentation for routine use in total knee arthroplasty.

Materials and Methods

Instruments were designed to take advantage of 3D-printing technology, particularly ensuring that all parts were pre-assembled, to theoretically reduce the time and skill required during surgery. Concerning functionality, ranges of resection angle and distance were restricted within a safe zone, while accommodating either mechanical or anatomical alignment goals. To identify the most suitable biocompatible materials, typical instrument shapes and mating parts, such as dovetails and screws, were designed and produced.


The Bone & Joint Journal
Vol. 98-B, Issue 7 | Pages 867 - 873
1 Jul 2016
Dalury DF

As the number of younger and more active patients treated with total knee arthroplasty (TKA) continues to increase, consideration of better fixation as a means of improving implant longevity is required. Cemented TKA remains the reference standard with the largest body of evidence and the longest follow-up to support its use. However, cementless TKA, may offer the opportunity of a more bone-sparing procedure with long lasting biological fixation to the bone. We undertook a review of the literature examining advances of cementless TKA and the reported results.

Cite this article: Bone Joint J 2016;98-B:867–73.


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 11 | Pages 1457 - 1461
1 Nov 2012
Krishnan SP Dawood A Richards R Henckel J Hart AJ

Improvements in the surgical technique of total knee replacement (TKR) are continually being sought. There has recently been interest in three-dimensional (3D) pre-operative planning using magnetic resonance imaging (MRI) and CT. The 3D images are increasingly used for the production of patient-specific models, surgical guides and custom-made implants for TKR.

The users of patient-specific instrumentation (PSI) claim that they allow the optimum balance of technology and conventional surgery by reducing the complexity of conventional alignment and sizing tools. In this way the advantages of accuracy and precision claimed by computer navigation techniques are achieved without the disadvantages of additional intra-operative inventory, new skills or surgical time.

This review describes the terminology used in this area and debates the advantages and disadvantages of PSI.