Posterior Knee Capsulotomy for the Relief of Patellofemoral Joint Pain: Long-Term Follow-up.

Lack of full extension of the knee is a disabling condition that sometimes needs to be treated by a posterior capsulotomy of the knee. However, it is not clear if the full extension acquired can be kept throughout long-time follow-up. We conducted a retrospective cohort study of 20 patients diagnosed with minimal flexion contracture of the knee who underwent open posterior capsulotomy between 1990 and 2010. All patients (100%) presented with a preoperative Lysholm's score classified as poor or fair (mean = 58.6 ± 13.8, 95% confidence interval [CI]: 52.3-64.9), but 14 patients (70%) experienced an improvement to good or excellent scores (mean = 87.6 ± 8.8, 95% CI: 83.6-91.6) after the follow-up. The mean preoperative angle of fixed flexion was 25.0 ± 9.1 degrees (95% CI: 20.8-29.2), and it decreased to 4.2 ± 4.1 degrees (95% CI: 2.3-6.1) after the follow-up. We conclude that posterior capsulotomy of the knee proved to be an effective procedure to treat properly patients with painful knees secondary to lack of full extension after 10.3 years of follow-up.

Interobserver and intraobserver reproducibility of hallux valgus angular measurements and the study of a linear measurement.

BACKGROUND: The intermetatarsal angle (IMA), the hallux valgus angle (HVA), and the lateral sesamoid malalignment in relation to the first metatarsal are among the most commonly employed parameters to estimate the severity of the deformity. The aim of this study was to compare HV angular measurements and a linear measurement among 4 observers to determine its intraobserver and interobserver reliability, to find out whether this linear measurement technique is more reproducible than those already-described angular measurements. METHODS: The IMA, the HVA, and the distance between the lateral cortex of the first metatarsal and the lateral cortex of the lateral sesamoid bone were measured from 50 standing, nonoperated hallux valgus feet. Radiographs were shuffled and reforwarded to the observers at a minimum interval of 30 days for a new measurement. RESULTS: When considering 2° of difference as significant, IMA and HVA measurements were not precise, showing low reproducibility for both intraobserver and interobserver assessment. Regarding the distance between the first metatarsal lateral cortex and the lateral sesamoid lateral cortex, when considering differences greater than 2 mm as significant, we observed higher precision and higher reproducibility. CONCLUSIONS: Angular measurements of hallux valgus deformity in anteroposterior standing radiographs that are manually performed with a goniometer are not precise and have low reproducibility. The linear measurement of the distance between the lateral cortices of the first metatarsal head and the lateral sesamoid demonstrated higher precision and higher reproducibility, and may be a cheap form to assess the correct indication of a distal osteotomy. LEVELS OF EVIDENCE: Diagnostic, Level II.

Comparison between a static and a dynamic technique for medial patellofemoral ligament reconstruction.

PURPOSE: The purpose of our study was to compare the technical difficulties and the results of the use of two different types of femoral graft fixation for medial patellofemoral ligament reconstruction in patients with patellar luxation. METHODS: Twenty-four matched pair patients, assigned to two groups of 12 patients each, underwent medial patellofemoral ligament reconstruction using one of two techniques: the adductor magnus rigid and the semitendinosus tendon dynamic femoral fixation. Results were assessed using a scale for activities of daily living before and after surgery. RESULTS: No statistical difference was detected between the groups despite one case of reluxation in the adductor magnus group. No major complication was observed in either group. Patients in the semitendinosus group felt subjectively better, and a larger number of patients in this group resumed the practice of sports. CONCLUSIONS: Even in the absence of significant differences, the present results suggest that a more dynamic femoral fixation is more advantageous than a rigid alternative. LEVEL OF EVIDENCE: Level III, therapeutic comparative study.

Mechanical changes induced by thermal stimulation in collagenous tissue.

Radiofrequency thermal stimulation is used as a therapeutic procedure for joint laxity, but its thermal effects are still controversial. Although collagen shrinkage may be expected, this conclusion is empirical and not universally accepted. The purpose of this study was to investigate the mechanical response of collagen to thermal stimulation. A longitudinal cut was made in rabbit Achilles tendons previously marked with monofilament sutures. The distance between the sutures was measured before the cut, just after it was made, and after 8 weeks. The results did not show any shrinkage or significant change in tendon resistance to traction 8 weeks after thermal stimulation; however, comparison with the opposite, normal tendon revealed a statistically significant increase in tendon stiffness.

Fixaçäo mecânico-biológica de ligamentos artificiais (próteses artificiais de partes moles): apresentaçäo de uma técnica original a partir de estudo imediato e a curto prazo em ovelhas / Mechanico-biological of artificial ligaments (artificial prosthesis of soft parts): presentation of an original technical as from of immediate and short term study in sheeps

Através de trabalho prospectivo, os autores estudaram em ovelhas o comportamento de cinco técnicas de fixaçäo de próteses ligamentares ao nível do joelho. Para tanto, foram utilizados critérios biomecânicos, radiológicos e histológicos. O tempo global e evoluçäo do projeto foi de dois anos, sendo que, na etapa in vivo, as ovelhas foram sacrificadas após três semanas, quatro meses e sete meses. Esses resultados foram comparados, quanto à resistência à traçäo, com o resultado preliminares obtidos em joelhos de ovelhas abatidas poucas horas antes dos testes. Dos métodos investigados, a fixaçäo com grampo metálico foi a menos eficaz, sendo o conjunto mecânico-biológico (parafuso + arruela metálica + arruela óssea) o que nos pareceu mais satisfatório