Analyzing the Accuracy of Digital Sizing on Long-Leg Alignment X-rays by Using a 1-Inch Ball Bearing: A Cheap and Effective Method.

Background and objective Sizing on digital films is important for implants and planning deformity correction. CT is the most accurate digital measurement method. We use a 1-inch ball bearing (cost: $1) to size our long-leg standing films (LLSFs) when planning deformity correction. In this study, we aimed to assess the accuracy of digital measurements calibrated by this method. Methods We conducted An IRB-approved study involving 25 patients having both an LLSF with a 1-inch ball bearing taped to the inner mid-thigh and a CT scanogram. The longest distance in the axial cut of the bilateral ankle, knee, and femoral heads of the CT images were compared to the same anatomic locations on LLSFs calibrated with the ball bearing using the online digital planning software DetroitBonesetter (DBS) and measurements from our Picture Archiving Communication Software (PACS). Five observers performed each measurement. Results The average measurement differences between the gold standard CT scan and LLSFs calibrated with DBS were as follows: 0.110 ± 0.432 mm (femoral head); 2.173 ± 0.0619 mm (knee); and 3.671 ± 0.30 mm (ankle). In PACS, they were as follows: 5.470 ± 0.381 mm (femoral head); 6.248 ± 0.712 mm (knee); and 1.806 ± 0.548 mm (ankle). The intraclass correlation coefficient for 600 measurements by five observers was 0.972. Conclusions The $1 ball-bearing sizing on DBS using LLSFs provides accuracy to <1 mm for the femoral head, 2 mm at the knee, and 3.7 mm at the ankle. It was significantly better than the PACS system for both the femoral head and knee (<0.001), while PACS was better at the ankle (<0.001).

Sub-chondroplasty Reduces Pain, Improves Function and Delays the Conversion to Arthroplasty in Patients with Advanced Knee Osteoarthritis: A Stratified Meta-analysis and Quality Assessment.

There is an ongoing interest in alternatives to total knee arthroplasty, as a means to delay inevitable replacement. A possible, minimally invasive, alternative is a sub-chondroplasty, involving interosseous injection of bone substitute materials such as calcium phosphate (CaPo4), platelet-rich plasma (PRP), bone marrow aspirate concentrate (BMAC) or Injectable demineralized bone matrix (iDBM) into the subchondral bone. Eleven clinical trials were found, investigating the effectiveness of sub-chondroplasties performed using CaPo4, PRP, BMAC, and iDBM. A non-stratified and stratified meta-analysis of the included studies were conducted to test for confounding variables across the trials. Non-stratified analysis, regardless of injectable type, revealed a significant improvement in the average Visual Analog Scale (VAS) score and postoperative Knee Injury and Osteoarthritis Outcome Score (KOOS) in patients post sub-chondroplasty, as compared to baseline. This analysis demonstrates that the sub-chondroplasty procedure reduces pain, improves function, and has lower risk of conversion to arthroplasty. (Journal of Surgical Orthopaedic Advances 32(2):065-074, 2023).