Patient specific instrumentation (PSI) for elective knee replacements in arthritic knees with severe deformities and in revision scenarios is becoming increasingly popular due to the advantage of restoring the limb axes, improved theatre efficiency and outcomes. Currently available systems use CT scan or MRI for pre-operative templating for design considerations with varied accuracy for sizing of implants. We prospectively evaluated 200 knees in 188 patients with arthritic knees with deformities requiring serial clinical assessment, radiographs and CT scans for PSI templating for TruMatch knee system (DepuySynthes, Leeds, UK). The common indications included severe arthritic deformities, previous limb fractures and in obese limbs with difficult clinical assessment. Surgical procedure was performed on standard lines with the customised cutting blocks. The ‘lead up’ time between the implant request and the operating date was 5 weeks on an average. We compared the pre op CT images and the best fit post-operative x- rays. The sizing accuracy for femur and tibia was 98.93 % and 95.75% respectively. All blocks fitted the femur and tibia. There were no bail outs, no cutting block breakage, 1 patient had residual deformity of 20 degrees, and 1 patient had late infection. The length of hospital stay, economic viability in terms of theatre turnover, less operating time, cost of sterilisation in comparison to conventional knee replacement surgery with other factors being unchanged was also assessed. The projected savings was substantial along with improved geometrical restoration of the knee anatomy. We recommend the use of PSI based on CT scan templating in difficult arthritic knees.
Computed tomography (CT) can be utilized to design patient specific instruments (PSI) for total knee arthroplasty (TKA). The PSI preoperative plans predict bone resection, anterior-posterior implant position, implant rotation and implant size. The purpose of this study was to compare preoperatively predicted implant sizes (tibia and femur) to the actual implanted sizes. Data were compiled from two surgeons, one in the United Kingdom (Surgeon 1, cruciate retaining) and one in the United States (Surgeon 2, posterior stabilizing). Both used the same primary TKA implant systems (Sigma® and Attune®; DePuySynthes®, Warsaw, Indiana). This is the largest comparison of CT-based PSI size accuracy between two implant systems. An international cohort of 396 CT-based PSI-TKA preoperative plans (TruMatch®)were compared to postoperative implant records. Data were retrospectively analyzed for Sigma®(n=351) and Attune® (n=45), both as separate cohorts and as a combined cohort (Sigma® + Attune®). Three analyses were performed: Tibia and femur plan accuracy, major size changes (femoral size change or tibial size change resulting in a femoral size change) and minor size changes (tibial size change not impacting femoral size). Inter-rater reliability analyses using ICC (intra-class correlation) and the Kappa statistic were performed to determine reliability and agreement among the groups. Combined TKA implant data (Sigma® + Attune®) for surgeons 1 and 2 were compared for accuracy between users utilizing different implant designs, cruciate retaining (CR) versus posterior stabilized (PS).Introduction
Methods
We evaluated the clinical outcome of arthroscopic labroplasty in 56 patients treated for shoulder instability owing to ligamentous laxity. In our technique, the antero-inferior labral capsular complex is detached and mobilised from the glenoid. It is advanced superiorly and plicated to create a new labrum, retensioning the capsule and decreasing the articular volume. Usually, a rotator interval plication is also added. Postoperatively, patients wear an adduction sling for three weeks, but movement is permitted within pain limits. The mean time to follow-up, when patients were clinically reviewed and assessed on the Walch-Du Play score, was 26 months (12 to 74). No intra-operative complications or nerve injuries were encountered. There was a single failure with frank redislocation. The mean Walch-Du Play score was 88/100 (10 to 100). Redundant capsule and a hypoplastic labrum are common in unstable shoulders owing to ligamentous laxity. The labroplasty creates a ‘bumper’ and addresses the excess of capsule. In our short-term experience, this arthroscopic technique is superior to the open capsular shift.
The supraspinatus tendon (SP) often ruptures. Gray established that the tendinous insertion always attaches to the highest facet of the greater tubercle of the humerus. Our osteological study of 124 shoulders in men and women between the ages of 35 and 94 years refocuses on the humeral insertion of the SP in relation to infraspinatus (IS) and teres minor (TM). We found type-I SFs (cubic) in 53 shoulders (43%) and type-II SFs (rectangular or oblong) in 21 (17%). Type-III (ellipsoid) SFs were present in 20 shoulders (16%) and type-IV (angulated or sloping) in 11 (9%). SFs were type V (with tuberosity) in 12 shoulders (10%) and type VI (pitted) in three (2%). The facet area of the SP, IP and TM varied from 49 mm, 225 mm and 36mm2. Of the three muscles, the IS facet was consistently the largest (p <
0.05) and shaped rectangularly. The SP inserted in a cubic or rectangular facet format in 75% of people. SP facet-size may relate to tendon strength, degeneration and rupture. This information may contribute to the understanding of tears of the rotator cuff.