Changes in biomechanical risk factors for knee osteoarthritis and their association with 5-year clinically important improvement after limb realignment surgery.

OBJECTIVE: To evaluate 5-year outcomes after lower limb realignment and test the hypothesis that surgery-induced changes in selected biomechanical risk factors for medial knee osteoarthritis (OA) are associated with clinically important improvements. DESIGN: We prospectively evaluated patient-reported outcomes, full-limb standing radiographs and gait biomechanics before, 6 months (surgery-induced change) and 5 years after medial opening wedge high tibial osteotomy (HTO) in 170 patients (46.4 ± 8.9 years, 135 males) with knee OA and varus alignment. Logistic regression tested the associations of 6-month changes in mechanical axis angle and knee adduction moment with achieving an increase of ≥10 points in the Knee injury and Osteoarthritis Outcome Score (KOOS)4 at 5 years, with and without adjusting for covariates. Gait data were also compared to existing data from healthy controls. RESULTS: Mean 5-year changes (95% confidence interval (CI)) were: KOOS4: +14.2 (10.8, 17.6); mechanical axis angle: +8.21° (7.58, 8.83); knee adduction moment: -1.49 %BW*Ht (-1.35, -1.63). The postoperative knee adduction moments were typically lower than values for healthy controls. When divided into quartiles, although all strata improved significantly, patients with reductions in knee adduction moment of 1.14-1.74 %BW*Ht (neither largest nor smallest changes) had highest 5-year KOOS4 scores. The 6-month change in knee adduction moment (odds ratios (OR) = 0.38; 95% CI: 0.22, 0.67), preoperative KOOS4 (OR = 0.96; 95% CI: 0.94, 0.99) and preoperative medial tibiofemoral narrowing grade (OR = 0.62; 95% CI: 0.37, 1.00) were negatively associated with having a 5-year clinically important improvement (C-statistic = 0.70). CONCLUSIONS: Substantial improvements in biomechanical risk factors and patient-reported outcomes are observed 5 years after medial opening wedge HTO. The surgery-induced change in load distribution during walking is significantly associated with long-term clinically important improvement.

Compartment pressure monitoring during anterior cruciate ligament reconstruction.

A prospective double blind randomized study was carried out using 20 healthy males with anterior cruciate ligament (ACL) insufficiency undergoing bone-patellar tendon-bone ACL reconstruction. The subjects were randomized into either water or saline irrigation and then underwent identical reconstructive procedures using an arthroscopic pump. Continuous preoperative, intraoperative, and postoperative pressures were monitored using the slit catheter technique. Blood pressure and compartment pressure measurements were continuously recorded and noted at all stages of the procedure. Mean preoperative anterior and posterior compartment pressures were similar in both groups. No significant differences were noted between the anterior and posterior compartments of each group. No difference between water and saline irrigation was identified throughout the procedure. In both groups, postoperative pressures were slightly lower in the anterior and posterior compartments compared with preoperative pressures, but not significantly.

Magnetic resonance imaging evaluation of the rotator cuff tendons in the asymptomatic shoulder.

Thirty shoulders in 20 volunteers (average age, 29 years; range, 17 to 49) with no shoulder symptoms or known abnormalities were scanned using magnetic resonance imaging. All scans were interpreted by one radiologist who was blinded to clinical data. Appearance of rotator cuff tendons on the images was graded. Grade 0 was normal, homogeneous low signal intensity structure. Grade 1 lesion was focal, linear, or diffuse intermediate signal through the tendon. Grade 2 lesion was high signal intensity within the tendon and less than full thickness. Grade 3 was high signal intensity through full thickness of the tendon. No supraspinatus or infraspinatus tendons were grade 0 (normal); all supraspinatus and infraspinatus tendons had grade 1 changes through the tendons; and 7 of 30 (23%) of the tendons had grade 2 changes. None of the 30 shoulders had grade 3 changes in the rotator cuff tendons. There is a wide array of abnormal magnetic resonance imaging signals in shoulders of young asymptomatic individuals, but they do not have full-thickness rotator cuff tears (grade 3 lesion). Nonenhanced magnetic resonance imaging may be of limited value in defining rotator cuff injury in a patient with shoulder pain unless a full-thickness rotator cuff tear is suspected clinically.

Osteoid osteoma of the neck of the talus: percutaneous, computed tomography-guided technique for complete excision.

CT-guided core drill excision of talar neck osteoid osteomas, in addition to other locations, appears to be a promising alternative to standard surgical treatment. As in this report, the technique is minimally invasive, which allows for complete, accurate excision and early return to activity.