Enhancing the radiological classification system from the distal femur to the proximal tibia

Introduction The inner diaphyseal diameter of the distal femur, at 20 cm from the lateral joint line, is the strongest risk factor for predicting aseptic loosening in total knee arthroplasty using rotating hinge prosthesis. In this context, the Citak classification has been introduced presenting three different types of the distal femur anatomy. The aim of the study is to develop a novel classification system for the proximal tibia. Materials and Methods Two-hundred patients with standard knee antero-posterior radiographs were included in this study. We measured the inner diameter of the tibia 16 cm distally from the tibial plateau and 3 cm distally from the tibial spine. The ratio between these two measurements was applied as the novel index ratio. Results According to the 25th and 75th percentiles, three groups can be clustered for each gender. A higher distribution of the type B pattern was found in female and male patients. However, type A with a narrow inner diaphyseal diameter was less common in female patients The median intra-observer reliability for rater 1 was 0.997. The inter-observer reliability was high (ICC 0.998). There was a moderate correlation between the AP diameter and height (r = 0,568); a low correlation between the AP diameter and weight (r = 0.376). The novel index shows no significant correlation between the index ratio and height (r = 0.082), weight (r = 0.014) or BMI (r= - 0.038). The novel index shows no statistically significant correlation between the index ratio and height (r = 0.082) or weight (r = 0.014) or BMI (r= - 0.038). Conclusion The novel classification presents three different types of tibia for each gender: type C has a wider inner diaphyseal diameter compared to type A with a narrow inner diaphyseal diameter. Type B has the widest distribution among the subjects.

Risk of total knee replacement after proximal tibia fracture: a register-based study of 7,841 patients

Background and purpose — Post-traumatic knee osteoarthritis following proximal tibia fracture (PTF) is a common complication that may lead to total knee replacement as secondary treatment (TKRS). We determined the risk of TKRS following PTF, whether treated nonoperatively or operatively, and compared the results with a 38-fold control group without prior PTF. Patients and methods — We identified all patients over 18 years of age in Finland with PTF treated during the period 2009–2018 from the Finnish Hospital Discharge Register (FHDR) and Finnish Arthroplasty Register (FAR). Age, sex, treatment method, follow-up time, and possible TKRS were recorded. Results — 7,701 patients were treated for PTF during the period 2009–2018. Over the 5.1-year (SD 3.1) follow-up, TKRS was performed in 340 (4.3%) patients with a prior PTF after a mean of 2.1 (SD 2.0) years post-fracture. TKRS was needed in 138 (3.7%, HR 1.8) patients in the nonoperatively treated group and in 202 (5.0%, HR 3.2) patients in the operatively treated group. Operative treatment, female sex, and high age were identified as risk factors for TKRS. The incidence of TKRS was highest during the first 2 years after fracture and remained elevated throughout the follow-up. Interpretation — Patients with a prior PTF had a 1.8- to 3.2-fold higher risk of TKRS compared with controls during the first 5 years post-fracture. Risk of TKRS was associated with an operatively treated PTF, female sex, and high age. The patients in the operative group likely sustained more complex fractures, while female sex and age may be explained by more osteoporotic bone quality.

Surgical management of giant cell tumor in adolescent by excision or curettage followed by fibular strut graft

<p class="abstract">Giant cell tumour (GCT) in adolescent is a rare tumour. It commonly occurs in skeletally mature patients aged between 20-40 years. In adults it is seen in epiphyseal region. In patients with intact physis, it arises from the metaphysis. Giant cells are more common in females. It is more common in the ends of long bones of distal end of femur, proximal tibia, and distal radius. 14 cases of surgical management of GCT by excision or curettage in adolescent followed by fibular strut graft. 1 year follow up of all cases of GCT in adolescent treated with excision or curettage followed by fibular strut graft was done. Out of 14 patients, 12 patients did not develop any recurrence of GCT. 2 patient developed recurrence after 6 months. All the patients were able to attain good range of movements 2 months after surgery. GCT in adolescent surgically treated with excision or curettage followed by fibular graft had excellent results in terms of recovery of daily activities, wound healing. Chances of recurrence more in patients treated with curettage and bone grafting.</p><p class="abstract"> </p>

Surgical Epicondylar Axis of the Knee and Its Relationship to the Axial Tibia Alignment in Knee Osteoarthritis: The Concept of Proximal Twist Tibia

The proximal tibia and distal femur are intimately linked with the biomechanics of the knee and they are to be considered in total knee arthroplasty (TKA). The aim of the present study was to evaluate the proximal tibial torsion (PTT) in relation to surgical epicondylar axis (SEA) in a healthy cohort and a pathological cohort affected by knee osteoarthritis (OA). We retrospectively analyzed computed tomography of OA knee of 59 patients before they underwent TKA and nonarthritic knee of 39 patients as control. Posterior condylar angle (PCAn), femoral tibial torsion (SEA-proximal tibial condyle [PTC] and SEA-PTT), PTT (PTC-PTT and posterior condylar axes [PCAx]-PTC), and distance between tibial tuberosity and the trochlear groove (TT-TG) were measured. No differences were found for gender, age, TT-TG, and PCAn angles. Statistically significant differences were found for all the other angles considered. Significant correlation was found between tibial torsion and SEA-PTT angles, between PCAx-PTC and SEA-PTC, between SEA-PTT and SEA-PTC, and between PCAx-PTC and SEA-PTT. All measures, except TT-TG and PCAn angles, showed high validity (area under the curve [AUC] > 75%) in associating with OA, with SEA-PTT displaying the highest validity with an AUC of 94.38%. This is the first study to find significant differences in terms of proximal tibia geometry and anatomy between nonarthritic and OA knees. From our results, we reported that OA group was characterized by a greater internal rotation of tibia with respect to SEAs compared with control group. Since the design of the study cannot evaluate a cause–effect relationship, further studies need to be performed to assess the potential implications of these anatomic differences for knee OA and arthroplasty surgeries.

Morphometric measurement of the proximal tibia to design the tibial component of total knee arthroplasty for the Thai population

Purpose This study evaluates the morphology of the Thai proximal tibia based on three-dimensional (3D) models to design the tibial component. Methods The 3D models of 480 tibias were created using reverse engineering techniques from computed tomography imaging data obtained from 240 volunteers (120 males, 120 females; range 20–50 years). Based on 3D measurements, a digital ruler was used to measure the distance between the triangular points of the models. The morphometric parameters consisted of mediolateral length (ML), anteroposterior width (AP), medial anteroposterior width (MAP), lateral anteroposterior width (LAP), central to a medial length (CM), central to a lateral length (CL), medial anterior radius (MAR), lateral anterior radius (LAR), and tibial aspect ratio (AR). An independent t-test was performed for gender differences, and K-means clustering was used to find the optimum sizes of the tibial component with a correlation between ML length and AP width in Thai people. Results The average morphometric parameters of Thai proximal tibia, namely ML, AP, MAP, LAP, CM, and CL, were as follows: 72.52 ± 5.94 mm, 46.36 ± 3.84 mm, 49.22 ± 3.62 mm, 43.59 ± 4.05 mm, 14.29 ± 2.72 mm, and 15.28 ± 2.99 mm, respectively. The average of MAR, LAR, and AR was 24.43 ± 2.11 mm, 21.52 ± 2.00 mm, and 1.57 ± 0.08, respectively. All morphometric parameters in males were significantly higher than those of females. There was a difference between the Thai proximal tibia and other nationalities and a mismatch between the size of the commercial tibial component and the Thai knee. Using K-means clustering analysis, the recommended number of ML and AP is seven sizes for the practical design of tibial components to cover the Thai anatomy. Conclusion The design of the tibial component should be recommended to cover the anatomy of the Thai population. These data provide essential information for the specific design of Thai knee prostheses.