Introduction. Tibial component loosening is a frequent cause of failure in primary total knee arthroplasty (TKA). Management options include isolated tibial component revision or full component revision. A full component revision is frequently selected by surgeons who are unfamiliar with the existing implant or have a “let's just start over attitude.” This option adds morbidity versus isolated tibial exchange. While isolated tibial exchange has lower morbidity, it is technically more challenging with regard to exposure and maintaining prosthetic stability. This study was designed to compare these two reconstructive options. Methods. Patients revised for isolated aseptic tibial loosening were identified from 2012–2017. Patients with revision implants, or those revised for infection, instability, osteolysis, or femoral component loosening were excluded. 161 patients met these criteria, 85 patients had an isolated tibial revision and 76 had revision of both components despite having only a loose tibial component. Patient demographics as well as clinical and radiographic outcomes were recorded for each cohort. Results. Patient demographical information, including age, gender, and BMI were statistically similar between the two cohorts. Median follow-up was 3.5 years. Supplemental metaphyseal fixation was used in 22 patients in the isolated tibial cohort and 19 of the full revision cohort. There was a higher incidence of radiographic loosening in the full component revision cohort (10.5% vs. 6.0%; p=0.28). There were five failures requiring revision in the isolated tibial cohort, two for sepsis, one for repeat isolated tibial loosening, one for femoral aseptic loosening, and one for an extensor mechanism disruption. There were eight failures in the full component cohort, three for patellar avascular necrosis, two for sepsis, one for repeat tibial loosening, one for arthrofibrosis, and one for a postoperative wound dehiscence. Conclusion. Isolated tibial revision for aseptic tibial loosening has similar clinical and radiographic results when compared to full component revision. Although no intraoperative complications were identified when revising the femur, there is the potential for complications unique to femoral revision. Femoral component revision for isolated tibial loosening is unnecessary and should be avoided provided adequate ligamentous stability can be obtained. Keywords: Aseptic loosening, Tibial loosening, revision total knee replacement, total knee replacement. For figures, tables, or references, please contact authors directly

PURPOSE OF STUDY. Periprosthetic fractures after total knee arthroplasty is a potentially serious and challenging complication and the incidence is continuously rising. The purpose of this study was to analyse the prevalence and analyse effectiveness of the various treatment methods for management of periprosthetic fracture of the distal femur after total knee arthroplasty, and to determine the clinical and radiographic results of patients following surgical treatment of these injuries. METHODS. We reviewed all patients with periprosthetic fractures after total knee arthroplasty treated surgically between 2003 and 2008 from the prospective hospital database. Medical and radiographic records were reviewed for patient characteristics, fracture characteristics, implant details, healing, and complications. Antero-posterior and lateral radiographs were reviewed at the time of admission, post-operatively and at follow up visits. Fractures were classified according to the Lewis and Rorabeck, Orthopaedic Trauma Association and the methods of Su and DeWal. RESULTS. 26 patients (average age= 77.6) had operative management for displaced fractures. Mechanical fall was the commonest mode of injury at a mean of 4.66 years post primary replacement. Locking plates was the commonest method of fixation for stable implant and displaced fractures [Lewis & Rorabeck type 2] and 2 patients had distal femoral replacements for unstable implants. Successful fracture healing within 6 months occurred in all but one patient. Full weight bearing mobilisation was achieved at 3 months in 94% and patients with distal femoral replacements achieved quickest recovery. CONCLUSIONS. Compared to the current literature, we had a satisfactory outcome in following individualised treatment of periprosthetic fractures after knee joint replacement. Periprosthetic femoral fractures around the knee commonly constitute a challenging problem and require an adequate analysis of fracture etiology and distal femoral replacement achieves satisfactory results in fractures with unstable implants

Background. Dual compartment knee replacement has been introduced to allow sparing of the cruciate ligaments and lateral compartment and preserve some biomechanics of knee function. Aim. To study the early clinical and radiographic results of this new prosthesis. Method. Patients who underwent dual compartmental knee arthroplasty performed by 2 surgeons over a period of one year were studied prospectively. All subjects in the study had advanced symptomatic osteoarthritis of the medial and patellofemoral joints but had an intact ACL and preserved lateral compartment. All patients received the Journey Deuce Dual Compartmental Knee System (Smith & Nephew, Inc, Memphis, Tenn) with Oxinium femoral component and modular tibial component. Follow-up with clinical evaluation, radiographs and Oxford knee scores were performed at 6 weeks, 6 months, 1 year, 2 years. Results. Mean follow up was 18months (range 12-24months). There were 15 patients (6 males, 9 females) with a mean age of 53 years (range, 46-68 years). Twelve of the 15 patients had their patella resurfaced. The mean inpatient stay was 4.5 days (range 3-11 days). The mean time taken for surgery was 80 minutes (range 77-112 minutes). Six of the 15 patients had poor results following surgery. Five out of six patients with poor results had tibial base plate loosening. This was confirmed either on plain x-rays, bone scan or at the time of revision surgery. Patients with tibial base plate loosening typically presented with persistent pain, particularly of the metaphyseal region when weightbearing and an effusion. One revision was performed for patellofemoral pain and maltracking. In total, three patients have already been revised and three are awaiting revision surgery. Further procedures were required in 2 patients. Conclusion. The Deuce dual compartmental knee replacement in its current design results in an unacceptably high rate of failure due to tibial base plate loosening. Some of these patients had good results in the early postoperative period which then deteriorated. Considering the high rates of failure we do not recommend this replacement with its current tibial plate design

Advances in polyethylene (PE) in total hip arthroplasty have led to interest and increased use of highly crosslinked PE (HXLPE) in total knee arthroplasty (TKA). Biomechanical data suggest improved wear characteristics for HXLPE inserts over conventional PE in TKA. Short-term results from registry data and few clinical trials are promising. Our aim is to present a review of the history of HXLPEs, the use of HXLPE inserts in TKA, concerns regarding potential mechanical complications, and a thorough review of the available biomechanical and clinical data.

Cite this article: Bone Joint J 2017;99-B:996–1002.

Objectives

The purpose of this study was to clarify the appearance of the reparative tissue on the articular surface and to analyse the properties of the reparative tissue after hemicallotasis osteotomy (HCO) using MRI T1ρ and T2 mapping.

In this study we randomised 140 patients who were due to undergo primary total knee arthroplasty (TKA) to have the procedure performed using either patient-specific cutting guides (PSCG) or conventional instrumentation (CI).

The primary outcome measure was the mechanical axis, as measured at three months on a standing long-leg radiograph by the hip–knee–ankle (HKA) angle. This was undertaken by an independent observer who was blinded to the instrumentation. Secondary outcome measures were component positioning, operating time, Knee Society and Oxford knee scores, blood loss and length of hospital stay.

A total of 126 patients (67 in the CI group and 59 in the PSCG group) had complete clinical and radiological data. There were 88 females and 52 males with a mean age of 69.3 years (47 to 84) and a mean BMI of 28.6 kg/m² (20.2 to 40.8). The mean HKA angle was 178.9° (172.5 to 183.4) in the CI group and 178.2° (172.4 to 183.4) in the PSCG group (p = 0.34). Outliers were identified in 22 of 67 knees (32.8%) in the CI group and 19 of 59 knees (32.2%) in the PSCG group (p = 0.99). There was no significant difference in the clinical results (p = 0.95 and 0.59, respectively). Operating time, blood loss and length of hospital stay were not significantly reduced (p = 0.09, 0.58 and 0.50, respectively) when using PSCG.

The use of PSCG in primary TKA did not reduce the proportion of outliers as measured by post-operative coronal alignment.

Cite this article: Bone Joint J 2015;97-B:56–63.