Management of a knee with valgus deformities has always been considered a major challenge. Total knee arthroplasty requires not only correction of this deformity but also meticulous soft tissue balancing and achievement of a balanced rectangular gap. Bony deformities such as hypoplastic lateral condyle, tibial bone loss, and malaligned/malpositioned patella also need to be addressed. In addition, external rotation of the tibia and adaptive metaphyseal remodeling offers a challenge in obtaining the correct rotational alignment of the components. Various techniques for soft tissue balancing have been described in the literature and use of different implant options reported. These options include use of cruciate retaining, sacrificing, substituting and constrained implants. This presentation describes options to correct a severe valgus deformity (severe being defined as a femorotibial angle of greater than 15 degrees) and their long term results. 34 women (50 knees) and 19 men (28 knees) aged 39 to 84 (mean 74) years with severe valgus knees underwent primary TKA by a senior surgeon. A valgus knee was defined as one having a preoperative valgus alignment greater than 15 degrees on a standing anteroposterior radiograph. The authors recommend a medial approach to correct the deformity, a minimal medial release and a distal femoral valgus resection of angle of 3 degrees. We recommend a sequential release of the lateral structures starting anteriorly from the attachment of ITB to the Gerdy's tubercle and going all the way back to the posterolaetral corner and capsule. Correctability of the deformity is checked sequentially after each release. After adequate posterolateral release, if the tibial tubercle could be rotated past the mid-coronal plate medially in both flexion and extension, it indicated appropriate soft tissue release and balance. Fine tuning in terms of final piecrusting of the ITB and or popliteus was carried out after using the trial components. Valgus secondary to an extra-articular deformity was treated using the criteria of Wen et al. In our study the majority of severe valgus knees (86%) could be treated by using unconstrained (CR, PS) knee options reserving the constrained knee / rotating hinge options only in cases of posterolateral instability secondary to an inadequate large release or in situations with very lax or incompetent MCL.Purpose
Methods
Management of severe bone loss in total knee arthroplasty presents a formidable challenge. This situation may arise in neglected primary knee arthroplasty with large deformities and attritional bone loss, in revision situations where osteolysis and loosening have caused large areas of bone loss and in tumor situations. Another area of large bone loss is frequently seen in periprosthetic fractures. Trabecular metal (TM) with its dodecahedron configuration and modulus of elasticity between cortical and cancellous bone offers an excellent bail out option in the management of these very difficult situations. Severe bone loss in the distal femur and proximal tibia lend themselves to receiving the TM cones. The host bone surfaces need to be prepared to receive these cones using a high speed burr. The cones acts as a filler with an interference fit through which the stemmed implant can be introduced and cemented. All areas of bone void is filled with morselised cancellous bone fragments. We present our experience of 64 TM cones (28 femoral, 36 tibial cones) over a 10-year period and our results and outcomes for the same. We have had to revise only one patient for recurrence of the tumor for which the cone was implanted in the first place. We also describe our technique of using two stacked cones for massive distal femoral bone loss and its outcomes. We found excellent osteointegration and new host bone formation around the TM construct. The purported role of possible resistance to infection in situations using the TM cones is also discussed. In summary we believe that the use of the TM cones offers an excellent alternative to massive allografts, custom and/or tumor implants in the management of massive bone loss situations.
Balancing accurate rotational alignment, minimal overhang, and good coverage during total knee arthroplasty (TKA) often leads to compromises in tibial component fit, especially in smaller-sized Asian knees. This study compared the fit and surgical compromise between contemporary anatomic and non-anatomic tibial designs in Japanese patients. Size and shape of six contemporary tibial component designs (A:anatomic, B:asymmetric, C-F:symmetric) were compared against morphological characteristics measured from 120 Japanese tibiae resected following TKA surgical technique. The designs were then digitally placed on the resected tibiae. Each placement selected the largest possible component size, while ensuring <1mm overhang and proper alignment (within 5° of neutral rotational axis). When a compromise on either alignment or overhang was required (due to smaller-sized component unavailable), the design was flagged as “no suitable component fit” for that bone. Tibial coverage was compared across designs. Next, 32 femora were randomly selected from the dataset onto which each design was evaluated in two placements, the first maximizing coverage without attention to rotation and the second enforcing rotational accuracy. Downsizing was identified if in the second placement, enforcing rotational accuracy, required a smaller component size compared the first placement. The degree of mal-alignment while maximizing coverage, the incidence of downsizing, and difference in coverage between the two placements were compared across designs. Statistical significance was defined at p<0.05.INTRODUCTION
METHODS
To evaluate the results of results of total knee replacement (TKA) in stiff and Ankylosed knees. A retrospective study was done to evaluate the results of total knee arthroplasty performed on 110 knees in 69 patients with spontaneously Ankylosed knees. The reasons of ankylosis was previous infection (pyogenic and tuberculous), inflammatory arthritis (rheumatoid arthritis, Juvenile rheumatoid arthritis, ankylosing spondylitis) and post –traumatic. The age at operation ranged from 30 to 65 years (average 42.8 years). Preoperative arc of movement was between 0 degrees and 20 degrees (average, 14 degrees). The difficulties encountered in surgical exposure were managed by using various extensile exposure techniques. Quadriceps snip was used in all case to avoid patellar avulsion. Follow-up ranged from 5 to 17 years (average, 9 years). The average postoperative arc of movement at final follow-up was 75.8 degrees, with a significant average gain of 61 degrees at final follow up. The average preoperative Hospital for Special Surgery Knee Score was 60 which improved to 75 at the final follow up. The average extensor lag was 8 degrees (range 0- 20 degrees). Complications included skin edge necrosis (35%), pyogenic infection in 3 patients, and a quadriceps tendon rupture in 1 patient. 4 knees were revised on account of component loosening. Total knee arthroplasty in Ankylosed knees does achieve correction of deformity with gain in range of motion leading to improved quality of life. Meticulous surgical technique is required to prevent complications. We believe that TKA in Ankylosed knees is a viable option.OBJECTIVE
Conclusions
Arthritic knees requiring total knee replacement may present with additional deformities located along the femur or tibia away from the articular region. These deformities may be congenital, developmental, associated with metabolic bone disease, or acquired as a result of malunited fractures or previous advocated for arthritic knee with ipsilateral extra-articular deformity. We undertook retrospective study to evaluate the results of total knee arthroplasty in arthritic knee with extra-articular deformity in 26 knees (24 patients). Sixteen deformities were in tibia and ten deformities were in femur. All patients underwent total knee arthroplasty with intraarticular bone resection and soft tissue balancing.Introduction
Methods
