Changes in subchondral bone morphology with osteoarthritis in the ankle.

Significant alterations to subchondral trabecular bone microarchitecture are observed in late-stage osteoarthritis (OA). However, detailed investigation of these changes to bone in the ankle are under-reported. This study aimed to fully characterise the trabecular morphology in OA ankle bone specimens compared to non-diseased (ND) controls using both standard and individual-trabecular segmentation-based (ITS) analyses. Ten ND tibial bone specimens were extracted from three cadaveric ankles, as well as five OA bone specimens from patients undergoing total ankle arthroplasty surgery. Each specimen was scanned using microcomputed tomography from which a 4 mm cuboidal volume was extracted for analysis. Morphological parameters for the subchondral trabecular bone were measured using BoneJ (NIH ImageJ) and 3D ITS for whole volumes and at each depth level in 1 mm increments. The results show an overall increase in bone volume fraction (p<0.01) and trabecular thickness (p<0.001) with OA, with a decrease in anisotropy (p<0.05). ITS analysis showed OA bone was composed of more rod-like trabeculae and plate-like trabeculae compared to ND bone. Numerous properties were depth dependent, but the results demonstrated that towards the subchondral bone plate, both rod- and plate-like trabeculae were thicker, rods were longer and plates had increased surface area. Overall, this study has verified key microstructural alterations to ankle subchondral bone that are found in other OA lower-limb joints. Depth-based analysis has highlighted differences of interest for further evaluation into the remodelling mechanisms that occur with OA, which is critical to understanding the role of subchondral bone microarchitecture in the progression of the disease.

The use of the 4.5 mm 90° titanium cannulated LC-angled blade plate in tibiotalocalcaneal and complex ankle arthrodesis.

BACKGROUND: Tibiotalocalcaneal arthrodesis is used to manage end stage arthritis, often associated with severe bone loss. The goal is to relieve pain through a stable, well-aligned hindfoot and ankle. We describe our initial results and outcome of ankle and tibiotalocalcaneal arthrodesis using a 90° blade plate. METHODS: We retrospectively reviewed the records of patients managed at our institution between 2010 and 2014. Twenty cases were identified who had either talocrural (n = 9) or TTC fusion (n = 11) with 1 patient having both ankle and then TTC fusion in separate sittings. RESULTS: Fusion occurred in 18 of the 20 cases (90%) with correction of angular deformity and restoration of hindfoot alignment. None of the 18 patients developed complications and all discharged to follow-up when independently mobile and satisfied with the outcome. CONCLUSIONS: This study demonstrated that using a 90° blade plate for ankle or TTC arthrodesis in a diverse group of complex primary and revision indications associated with severe deformity and bone loss resulted in a high rate of bony union and stable deformity correction.

Medial displacement calcaneal osteotomy using minimally invasive technique.

BACKGROUND: Medial displacement calcaneal osteotomy is a common procedure often used as part of pes planovalgus deformity correction. Traditionally the osteotomy is performed using a direct lateral or extended lateral approach, which may carry the risk of wound problems, infection and neurovascular injury. The authors describe a minimally invasive technique to perform the osteotomy and achieve the desired correction. The article illustrates our experience and learning curve with the use of this technique as an option for calcaneal osteotomy. METHODS: We retrospectively reviewed the records of a sequential series of patients since 2011 whose calcaneal osteotomies were performed by 2 surgeons, after cadaveric training using a minimally invasive operative approach. Prior to 2011, similar surgeries, performed by the senior authors, were undertaken using a direct lateral approach. Thirty cases were identified; 29 had tibialis posterior reconstruction coupled with calcaneal osteotomy for acquired flexible planovalgus deformity and 1 patient had surgery for a malunited calcaneal fracture. RESULTS: Radiological and clinical union occurred in all 30 cases (100%). The radiographs of all cases were reviewed by a specialist musculoskeletal radiologist. There were no neurovascular or wound complications. All patients had restoration of neutral hindfoot alignment. One patient required screw removal after union, resolving all symptoms. CONCLUSION: This series suggests that minimally invasive calcaneal osteotomy surgery can achieve excellent union rates aiding correction of deformity with no observed neurovascular or soft tissue complications. For surgeons experienced in open surgery, there is a short learning curve after appropriate training.

A prospective randomised study of minimally invasive midvastus total knee arthroplasty compared with standard total knee arthroplasty.

INTRODUCTION: Proposed advantages of minimally invasive surgery include shorter hospital stay, less blood loss, and a greater range of motion but potential concerns are raised about both prolonged learning curves and a compromise in exposure leading to implant malposition. PATIENTS AND METHODS: This powered study evaluates the outcomes of 80 patients randomised to have mini-midvastus (MMV) approach or standard medial parapatellar (MPP) approach. Rehabilitation protocols and discharge criteria were standardised. Patients were discharged home directly, capable of safe independent care. Validated outcome measures were recorded post-operatively at intervals up to 1 year. Independent, blinded review of post-operative x-rays was obtained. RESULTS: Length of stay was similar in the MMV and MPP groups (median 3.73 days vs. 3.75 days). No statistically significant differences were detected in either the demographic data or any intra-operative variable apart from blood loss and incision length. No statistically significant difference in clinical outcome measures (Oxford/Knee Society Scores) or radiographic analysis was observed. CONCLUSION: The MMV approach does not appear to confer any clinically significant benefit apart from a smaller surgical scar, compared to the MPP surgical technique. Level of evidence I: randomised control trial. R.E.C. 040301.