Thomas Lind

Fracture stage 4 of the lateral talar dome treated arthroscopically using biofix for fixation

A stage-4 osteochondral fracture of the anterolateral part of the talar dome in a 42-year-old sports-active woman was treated arthroscopically using biodegradable fixation [polyglycolic acid/(Biofix)]. She returned to the previous sport after 3 months without any complaints and, 15 months later, she is still without any symptoms from the ankle joint. A computed tomography scan after 15 months showed normal conditions. The technique is described, and arthroscopic surgery is proposed in the treatment of osteochondral lesions of the anterior part of the talar dome.

Ultrasonographic detection of foreign bodies in soft tissue

SummaryThe usefulness of ultrasound in the detection of foreign bodies was examined in a blind study in human cadavers using glass, plastic and wood as foreign bodies. Of 65 foreign bodies placed in 102 cicatrices, 58 were found using a 5 MHz transducer. The sensitivity was 89% and the specificity 93% making ultrasound a useful clinical tool for this purpose.

The Effect of Preoperative Intra-Articular Methylprednisolone on Pain After TKA: A Randomized Double-Blinded Placebo Controlled Trial in Patients With High-Pain Knee Osteoarthritis and Sensitization

In a randomized, double-blind, placebo controlled trial, we investigated the postoperative analgesic effect of a single intra-articular injection of 40 mg methylprednisolone acetate (MP) administered 1 week before total knee arthroplasty (TKA). Forty-eight patients with high pain osteoarthritis (≥5 on a numeric rating scale during walk) and sensitization (pressure pain threshold <250 kPa), aged 50 to 80 years and scheduled for primary unilateral TKA under spinal anaesthesia were included. The primary outcome was the proportion of patients with moderate/severe pain during a 5-m walk test 24 hours postoperatively. Secondary outcomes included pain at 48 hours, during the first 14 days, sensitization (quantitative sensory testing with pressure pain threshold and wind-up from temporal summation), and inflammatory changes (systemic C-reactive protein, intra-articular interleukin [IL]-6). No difference in the proportion of patients with moderate/severe pain was found between MP/placebo groups at 24 hours (67% and 74%, χ2 = .2, P = .63, odds ratio = .7, 95% confidence interval = .2-2.8) or at 48 hours (57% and 68%, χ2 = .5, P = .46, odds ratio = .6, 95% confidence interval = .2-2.3), and no difference between groups in postoperative sensitization was found (P > .4) despite reduced preoperative intra-articular inflammation (IL-6) in the MP group versus placebo (median change in IL-6 = -70 pg/mL, interquartile range = -466 to 0 vs. 32 pg/mL, interquartile range = -26 to 75, P = .029). Alternative central or peripheral analgesic interventions in this high-risk group are required. PERSPECTIVE Peripherally driven inflammatory pain and nociceptive changes before TKA has been suggested to be a cause for increased acute postoperative pain. However, preoperative intra-articular MP in patients with high pain osteoarthritis and sensitization did not reduce acute post-TKA pain or sensitization despite a preoperative reduction of intra-articular inflammatory markers.

Sonography in soft-tissue trauma of the shoulder

Seventy-five patients with soft-tissue trauma in the shoulder region were examined by ultrasonography. Normal conditions were found in 21 patients, distension of the acromioclavicular joint in 17, muscle hematoma or edema in 9, biceps tendinitis in 8, hematoma or partial rupture of the biceps tendon in 5, rupture of the biceps tendon in 1, and supraspinatus tendinitis or partial rupture in 14. A correlation was found between the sonography and clinical course; normal sonography was consistent with recovery in less than 1 week, whereas patients with pathologic changes in the supraspinatus or biceps tendon generally had symptoms for at least 1 month. We concluded that sonography is a useful diagnostic tool for evaluation of soft-tissue trauma in the shoulder.

Comparison of a novel porous titanium construct (Regenerex®) to a well proven porous coated tibial surface in cementless total knee arthroplasty — A prospective randomized RSA study with two-year follow-up

BACKGROUND Regenerex is a novel porous titanium construct with a three-dimensional porous structure and biomechanical characteristics close to that of normal trabecular bone. The aim of this study was to compare this novel construct to a well-proven porous plasma sprayed tibial (PPS) implant after total knee arthroplasty. METHODS Sixty-one patients scheduled for an uncemented TKA were randomized to receive either a novel highly porous titanium construct Regenerex or the PPS tibial component. Radiostereometric analysis of the tibial components was performed postoperatively and at three, six, 12, and 24months with measurements of migration (segment motion and maximum total point motion (MTPM)). RESULTS Knee and function scores improved significantly from preoperatively to two-year follow-up. For both the Regenerex and the PPS the majority of migration appeared during the first three months and then stabilized. No statistically significant differences in MTPM were found in any follow-up between three and 24months. The Regenerex group had a lower migration rate between 12 and 24months compared with the PPS implants (p=0.03) but the PPS group had an initial significantly lower subsidence (p=0.04). CONCLUSION In conclusion the Regenerex implant could prove an effective scaffold material for coating of uncemented implants but did no better than the PPS component at 24months of follow-up. ClinicalTrials.gov identifier: NCT01936415.

Monoblock versus modular polyethylene insert in uncemented total knee arthroplasty: A randomized RSA study with 2-year follow-up of 53 patients

Background and purpose — Backside wear of the polyethylene insert in total knee arthroplasty (TKA) can produce clinically significant levels of polyethylene debris, which can lead to loosening of the tibial component. Loosening due to polyethylene debris could theoretically be reduced in tibial components of monoblock polyethylene design, as there is no backside wear. We investigated the effect of 2 different tibial component designs, monoblock and modular polyethylene, on migration of the tibial component in uncemented TKA. Patients and methods — In this randomized study, 53 patients (mean age 61 years), 32 in the monoblock group and 33 in the modular group, were followed for 2 years. Radiostereometric analysis (RSA) was done postoperatively after weight bearing and after 3, 6, 12, and 24 months. The primary endpoint of the study was comparison of the tibial component migration (expressed as maximum total point motion (MTPM)) of the 2 different implant designs. Results — We did not find any statistically significant difference in MTPM between the groups at 3 months (p = 0.2) or at 6 months (p = 0.1), but at 12 and 24 months of follow-up there was a significant difference in MTPM of 0.36 mm (p = 0.02) and 0.42 mm (p = 0.02) between groups, with the highest amount of migration (1.0 mm) in the modular group. The difference in continuous migration (MTPM from 12 and 24 months) between the groups was 0.096 mm (p = 0.5), and when comparing MTPM from 3–24 months, the difference between the groups was 0.23 mm (p = 0.07). Interpretation — In both study groups, we found the early migration pattern expected, with a relatively high initial amount of migration from operation to 3 months of follow-up, followed by stabilization of the implant with little migration thereafter. However, the modular implants had a statistically significantly higher degree of migration compared to the monoblock. We believe that the greater stiffness of the modular implants was the main reason for the difference in migration, but an initial creep in the polyethylene metal-back locking mechanism of the modular group could also be a possible explanation for the observed difference in migration between the 2 study groups.

Bone Remodeling of the Distal Femur After Uncemented Total Knee Arthroplasty—A 2-Year Prospective DXA Study

Loss of bone stock as a response to the bone trauma, immobilization, and stress shielding related to joint replacement surgery increases the risk of fracture of the distal femur after total knee arthroplasty. Previous studies of uncemented femoral components have reported very high levels of bone loss in the distal femur. This study investigates the adaptive bone remodeling of the distal femur after uncemented total knee arthroplasty. We performed a 2-year follow-up of 53 patients (mean age 61.5 [38-70] years, F/M = 27/26, body mass index 29.5) who because of osteoarthritis received an uncemented total knee arthroplasty. All patients received a NexGen CR-Flex Porous Femoral Component. Measurements of bone mineral density of the distal femur using dual-energy X-ray absorptiometry were performed postoperatively and after 3, 6, 12, and 24 months. Bone mineral density (g/cm2) was measured in 3 regions of interest in the periprosthetic bone of the distal femur. Repeated measures analysis of variance and Tukey post hoc test for bone mineral density changed over time (p < 0.05 were considered significant). In the distal femur, significant changes in bone mineral density were seen after 24 months of follow-up, and bone mineral density decreased by 23.6% in the anterior region behind the anterior flange of the prosthesis (p < 0.001), 10.1% in the posterior region (p < 0.001), and 5.5% in the most proximal region (p < 0.001). We found highly significant bone mineral change in the distal femur after uncemented total knee arthroplasty, most pronounced in the anterior region, where a decrease in bone mineral density of almost 25%, was seen. Taking the expected age-related decay in bone mineral density in this age group into consideration, the decrease was substantial and must be considered to predispose to periprosthetic fractures.