Avascular necrosis of the femur head (AVNFH) is a debilitating disease caused due to the use of alcohol, steroids, following trauma or unclear (idiopathic) etiology, affecting mostly the middle aged population. Clinically AVNFH is associated with impaired blood supply to the femoral head resulting in bone necrosis and collapse. Although Homocysteine (HC) has been implicated in AVNFH, levels of homocysteine and its associated pathway metabolites have not been characterized. We demonstrate elevated levels of homocysteine and concomitantly reduced levels of vitamins B6 and B12, in plasma of AVNFH patients. AVNFH patients also had elevated blood levels of sodium and creatinine, and reduced levels of random glucose and haemoglobin. Biophysical and ultrastructural analysis of AVNFH bone revealed increased remodelling and reduced bone mineral density portrayed by increased carbonate to phosphate ratio and decreased Phosphate to amide ratio together with disrupted trabeculae, loss of osteocytes, presence of calcified marrow, and elevated expression of osteocalcin in the osteoblasts localized in necrotic regions. Taken together, our studies for the first time characterize the metabolomic, pathophysiological and morphometric changes associated with AVNFH providing insights for development of new markers and therapeutic strategies for this debilitating disorder.

Purpose To evaluate the clinico-radiological outcome of complex tibial plateau fractures treated with Ilizarov external fixation with or without minimal internal fixation. Methods This retrospective review was conducted on all the cases of Schatzker types V and VI tibial plateau fractures treated by Ilizarov external fixation between July 2006 and December 2015 with the minimum follow-up duration of one year. There were 30 patients: 24 males and 6 females, mean age 43.33 years, and mean follow-up 3.6 years. Three of them were open fractures; 15 cases were Schatzkertype V fractures and the other 15 type VI. According to AO/OTA classification, there were 11 type C1, 12 C2 and 7 type C3 fractures. Outcome assessment was made with American Knee Society Score (AKSS) and Rasmussen's Radiological Score (RRS) at final follow-up. Results Out of the 30 cases, mini-open reduction was performed in 7, bone graft in 4, minimal internal fixation in 10 and knee temporary immobilisation in 11 patients. Mean duration of external fixation was 11.8 weeks. All fractures united. Pin tract infections in 7 and common peroneal neuropathy in 2 patients were self-limiting. Two patients had axial misalignment of less than 10°. At final follow-up, the mean knee range of motion was 114.7, mean AKSS 81.5 and mean RRS 16.7. On statistical analysis, Schatzker type of fractures, use of minimal internal fixation and knee-spanning did not influence the final outcome. Conclusion Ilizarov external fixator with or without minimal internal fixation provides acceptable outcome for complex tibial plateau fractures. Care must be taken to look for minor loss of alignment, especially in Type VI Schatzker fractures after removal of the fixator. However small sample size precludes firm conclusions.

Purpose It is not shown whether anatomical variations exist in valgus arthritic limbs as to support individualized component and limb alignment. The null hypothesis was that there was no phenotypic variation of coronal femoro-tibial morphology in valgus knees. The aim was to determine whether distinct phenotypes of valgus knees could be identiied to help surgical planning and classifying valgus knees for outcome studies. Methods Full-leg weight-bearing radiographs of 233 knees (182 preoperative; 51 of contralateral arthritic knee) were measured for HKA (hip-knee-ankle angle), VCA (valgus correction angle), mLDFA (lateral mechanical distal femoral angle), aLDFA (lateral anatomical distal femoral angle), MPTA (medial proximal tibial angle), MNSA (medial neck shaft angle), TAMA (angle between tibial mechanical and anatomical axes), and TBA (tibial bowing angle). Results Nine phenotypes were identiied encompassing all 233 knees which could be clubbed into 4 broad types. Type 1 Neutral knees (12.5%) had almost normal values (mean VCA 5.3°, mLDFA 86.9°, aLDFA 81.1°). Type 2 'Intra-articular valgus' (22.7%) showed lateral compartment bone loss (mean mLDFA 83.9°; MPTA 90.2°). Type 3 'Extra-articular valgus' (35.2%) had extra-articular deformity: 3a showed valgus femoral bowing (mean VCA 2.7°); 3b valgus tibial bowing; 3c showed valgus tibial bowing with lateral femoral condyle wear (mean mLDFA 84.3°). Type 4 'Varus' type (29.6%) had features of varus knees: 4a had varus femoral bowing (VCA 8.3°); distal femur in 4b was akin to varus knees (mean mLDFA 89.3°) with lateral tibial bone loss (mean MPTA 91.2°). 4c had varus tibial bowing and deicient lateral femoral condyle (mLDFA 83.7°). 4d had varus tibial bowing and lateral tibial bone loss (mean MPTA 89.8°). ConclusionsThe study identiied four broad groups of valgus arthritic knees with nine phenotypes based on coronal plane variations in femoro-tibial morphology. This study may be of value in planning and performing corrective osteotomies, and planning the optimal position of femoral and tibial components in unicompartmental and total knee arthroplasty. The classiication presented in this study may aid in categorizing valgus knees for outcome studies. Level of evidence IV.

Purpose Recommendations for resecting distal femur and proximal tibia in mechanical and anatomical alignment techniques are standardized. Kinematic alignment propagates individualizing resection planes. Whether significant variation exists, to warrant departure from standardized resection planes, has not been shown thus far in a large cohort of knees and with a wide range of varus deformity. The null hypothesis of this study was that there was no phenotypic variation in varus osteoarthritic knees. The aim of this paper was to determine whether distinct phenotypes could be identified, based on variations in coronal femoral and tibial morphology, which could aid in surgical planning and categorizing varus knees for future studies. Methods 2129 full-leg weightbearing radiographs were analyzed (1704 preoperative; 425 of contralateral arthritic knee). Measurements made were of HKA (hip-knee-ankle angle), VCA (valgus correction angle), mLDFA (lateral mechanical distal femoral angle), aLDFA (lateral anatomical distal femoral angle), MPTA (medial proximal tibial angle), MNSA (medial neck shaft angle), TAMA (angle between tibial mechanical and anatomical axes), and TPDR (percentage length of tibia proximal to extra-articular deformity). Results Seven distinct types were identified covering 2021 knees, reducible to 4 broad phenotypes: 11% were Type 1 'Neutral' knees showing values close to reported normal knees (mean VCA 5.5°, mLDFA 87°, aLDFA 81°). 38% were Type 2 'Intra-articular varus' with medial intra-articular bone loss (mean mLDFA 90.9°, MPTA 85.4°, VCA of 5.7°). 41% were Type 3 'Extra-articular varus' with extra-articular deformity (EAD). Type 3a had proximal tibial EAD; Type 3b had tibial diaphyseal EAD; Type 3c had femoral EAD (mean VCA 8.7°, HKA 166°), and severe medial bone loss (mean mLDFA 92°, MPTA 83°). 9% were Type 4 'Valgoid type' with features of valgus knees: Type 4a had medial femoral bowing (mean VCA 2.9°); Type 4b had significant distal femoral valgus (mean mLDFA 85.3°, aLDFA 78.6°). Conclusions The null hypothesis that there was no phenotypic variation in varus osteoarthritic knees was rejected as considerable variation was found in coronal morphology of femur and tibia. Four broad phenotypic groups could be identified. Plane of the knee joint articular surface was quite variable. This has relevance to planning and performance of corrective osteotomies, unicompartmental and total knee arthroplasty. Level of Evidence III, retrospective cohort study.