Morphology of the posteromedial fragment in pertrochanteric fractures: A three-dimensional computed tomography analysis.

BACKGROUND: In this study we describe the morphology of the posteromedial fragment in pertrochanteric fractures using 3D CT scans and answer two questions 1) Do differences exist between the 3D CT appearances of posteromedial fragments and the depictions made in the AO classification 2) Does the posteromedial fragment affect stability in pertrochanteric fractures, in terms of fracture collapse? METHODS: Preoperative CT scans of eight 31-A1 and fifty 31-A2 fractures were analysed. The presence of PM fragment, its fragmentation, greater trochanter (GT) involvement, lesser trochanter (LT) fragment size (in terms of its posterior and medial extent as well as LT length), LT fragment displacement (in terms of medial displacement and rotation) were determined. All fractures were treated with a DHS. Fracture collapse was determined on postoperative radiographs. The relationship between fracture collapse and patient factors including age, gender, fracture type (A1 versus A2), characteristics of the posteromedial fragment, and the presence of a lateral wall fracture were determined. RESULTS: Three out of eight 31-A1 fractures demonstrated a separate GT fragment (three part fracture). Out of the 50 31-A2 fractures, 12 had a single PM fragment, which included the LT and GT in continuity. The more common four part fractures seem to form by further fragmentation of this basic form. In A2 fractures, the GT was almost always broken and the broken fragment comprised a mean 56% of normal GT. The LT fragment involved an average of 74% of the posterior wall, and an average of 36% of the medial wall of the proximal femur. Larger LT fragments were less displaced as compared to smaller fragments. Univariate regression analyses revealed that fracture collapse was significantly correlated with fracture type (A1 versus A2, p 0.036), GT size (p 0.002) and the presence of a lateral wall fracture (p<0.001). CONCLUSIONS: This study revealed some important differences between the 3D CT appearances and AO classification of pertrochanteric fractures. Further, neither fragmentation of the posteromedial fragment, nor the size of the lesser trochanter fragment was found to predict stability in pertrochanteric fractures. A perioperative lateral wall fracture is the main determinant of stability in these fractures.

Epidemiological characteristics of patellofemoral osteoarthritis in elderly Koreans and its symptomatic contribution in knee osteoarthritis.

BACKGROUND: Many studies have reported the prevalence of knee osteoarthritis (OA) but have invariably focused on the tibiofemoral (TF) joint and overlooked the patellofemoral (PF) joint. Accordingly, little epidemiological information is available regarding the PF OA. The purpose of the current study was to document the epidemiological characteristics of PF OA in elderly Koreans. METHODS: Radiographic assessment was performed for 681 elderly (≥65 years old) Koreans recruited from a community, and symptom severity was evaluated using Western Ontario and McMaster Universities Index (WOMAC) and Short Form-36 (SF-36) scales. Prevalence of different categories of knee OA (isolated PF OA, isolated TF OA and combined PF and TF OA) was calculated. The symptoms of isolated PF OA group and non-OA group were compared. RESULTS: The overall prevalence of OA was 22.0% in the PF compartment and 34.1% in the TF compartment. The prevalence of isolated PF OA, isolated TF OA, and combined PF and TF OA was 3.8%, 17.8%, and 19.2%, respectively. Female sex, aging, and obesity were not associated with isolated PF OA. No significant differences were found in any clinical outcome scales between the isolated PF and non-OA groups. CONCLUSION: This study documents that OA in the PF joint is common in elderly Koreans, but isolated PF OA is rare. Demographic risk factors are not associated with isolated PF OA, suggesting that isolated PF OA may have a different pathophysiology from other types of knee OA. Our study also indicates that the presence of isolated PF OA should not be construed to be responsible for clinical symptoms.

Which AO/OTA 31-A2 pertrochanteric fractures can be treated with a dynamic hip screw without developing a lateral wall fracture? A CT-based study.

PURPOSE: To determine whether radiographic measurements derived from standard computed tomography (CT) evaluation can be used to predict likelihood of a peri-operative lateral femoral wall fracture in AO/OTA 31-A2 pertrochanteric fractures treated with a dynamic hip screw (DHS). METHODS: Fifty-one patients with AO/OTA 31-A2 classified pertrochanteric fractures were evaluated using a pre-operative CT scan of the pelvis with both hips. Dimensions of the lateral wall were calculated for each patient using four parameters: (1) height of the lateral wall above the vastus ridge; (2) circumference of the lateral wall 2 cm below the vastus ridge at an angle of 135°; this circumference was further divided into an anterior, lateral and posterior component; (3) cortical thickness at the centre of the lateral component of the lateral wall; and (4) cortical index. All patients were treated with a 135° DHS. Postoperative radiographs were assessed for lateral femoral wall fracture. RESULTS: Patients with a lateral wall fracture (17/51) had a smaller circumference (4.47 cm vs 5.44 cm p value <0.001) as well as a lower height of the lateral femoral wall (1.37 cm vs 2.21 p value < 0.001). Analysis of the three components of the circumference revealed a significant difference for the anterior component only and not for the lateral and posterior components. There was no statistical difference in the cortical thickness or cortical index in the two groups. The cutoff values for height of the lateral wall and anterior component were calculated using ROC curves and found to be 1.68 cm (AUC 0.918) and 2.10 cm (AUC 0.851) respectively. CONCLUSION: AO/OTA 31-A2 pertrochanteric fractures with a lateral wall height of > 1.68 cm and an anterior component of > 2.10 cm in circumference are not likely to sustain a lateral wall fracture when treated with a DHS.

Anterolateral Portal Is Less Painful than Superolateral Portal in Knee Intra-Articular Injection.

PURPOSE: Intra-articular knee injections are commonly performed in clinical practice for treating various knee joint disorders such as osteoarthritis and rheumatoid arthritis. When selecting the portal for injection, not only intra-articular needle accuracy but also procedural pain should be taken into consideration. The purpose of this study was to determine whether injection through anterolateral portal provokes less pain and provides better pain relief compared to superolateral portal. MATERIALS AND METHODS: A total of 60 patients with primary osteoarthritis of the knee receiving intra-articular injections were randomized into 2 groups according to the type of portal approach; anterolateral or superolateral. All patients received hyaluronic acid (20 mg) and triamcinolone (40 mg) as the first injection followed by second and third injections of hyaluronic acid on a weekly basis. Underlying knee pain, procedural pain, and knee pain at 4 weeks were evaluated using visual analogue scale (VAS). RESULTS: Injection through anterolateral portal provoked less pain (VAS, 1.5±1.3) than the superolateral portal (VAS, 1.5 vs. 2.7; p=0.004). No differences were found in the degree of pain relief at weeks between the two groups (p=0.517). CONCLUSIONS: We recommend the use of anterolateral portal for intra-articular knee injection as it provokes less pain and comparably short-term pain relief than the superolateral portal.