Background. Jumper's knee is the result of violent and repeated contractions of quadriceps muscle caused by rapid acceleration and deceleration, jumping and kicking that load on patellar tendon stressing its mechanical resistance. The porpose of this retrospective study is to analyze the results, after the debridment of the patellar tendon and the patellar apex abrasion performed by arthroscopy, at a mean follow-up of seven years. Methods. From 1996 to 2006, sixty-four patients (seventy-three knees) affected by jumper's knee underwent surgical tretment after failure of nonoperative treatment. All knees were operated on by the same surgeon using the same surgical technique: arthroscopic debridement of the articular face of patellar tendon and arthroscopic abrasion of patellar apex. Pre-operative and post-operative evaluation was made according to IKDC score, Lysholm Knee Scale and VISA-P score. Results. The pre-operative subjective IKDC score was 52,96. This score significantly increased to 94,72 at 12 months post-operation, and has remained nearly constant at 10 years of follow-up. The mean pre-operative Lysholm Knee Scale was 51,57 and significantly increased to 86,48 at 12 months post-operation again remaining nearly constant at 10 years of follow-up. The score according to VISA-P which was pre-operatively 35,32 increased to 69,80 at 12 months post-operation and was 69,35 at 10 years of follow-up. Nineteen of the twenty-seven patients who were involved in competitive sport continued it at the same level and twenty-four were symptoms-free. Conclusions. For these satisfactory results, for the low aggressivity of this surgery, for the short recovery time and the faster return to sport we think that the debridment of the patellar tendon and the patellar apex abrasion performed by arthroscopy is the technique to prefer for surgical treatment of Jumper's Knee

Introduction. Delayed onset muscle soreness (DOMS) in the quadriceps is frequent in runners finishing a marathon race, and may result in several days of discomfort and pain. There is an increasing clinical evidence that noninvasive, pulsed electromagnetic field therapy (PEMF) can have physiological effect on inflammation and tissue repair. The purpose of this pilot study was to investigate the effect of PEMF on quadriceps muscle soreness in marathon runners and to use the data to calculate an appropriate sample size for a subsequent study. Material and methods. The design was a randomized double-blind prospective study covering a 5 days period after completion of a beach marathon. After the marathon all 74 runners that completed the 42.195 km were asked to participate in the study. Forty-six agreed to enter the study and were block randomized into an intervention group or a control group. The intervention group received an active pulsed electromagnetic field device, and the control group received a sham device. The sham devices were used in exactly the same manner but produced no electromagnetic field. The active PEMF device does not produce heat or cause any sensation in the tissue allowing participants to be blinded to treatment. The pulsed electromagnetic field signals of a 2-msec burst of 27.12-MHz sinusoidal waves were repeated at two bursts per second. Peak magnetic field was 0.05 G, which induced an average electric field of 10 mV/cm in the tissue with an effect of 7.3 mW/cm3. All subjects were instructed to place the device on the most painful area of the quadriceps for 20 minutes four times a day. Pain intensity was measured three times a day with the Visual Analogue Scale (VAS) during a 90o squat with a self-administered questionnaire. Data were non-parametric and compared with a two-sample Wilcoxon rank-sum test. Results. 39 of the 46 runners returned the questionnaire. There was no difference in characteristiscs between the groups. There was a clear trend towards a smaller amount of pain in the intervention group compared to the control group at day one and two. Subjects in the intervention group reported on average 20mm (40 %) less pain on day one and approximately 10mm (40 %) less pain on day two(p=0.17−0.27). At day three, four and five, there were no clear differences in pain intensity reported in the two groups. Using the data from the current pilot study a sample size of 41 subjects in each group are needed to show a statistically significant difference between groups((power 0.90, alpha 0.05 one-sided test)). Conclusion. This pilot study indicate that PEMF can reduce quadriceps DOMS following a marathon race. However a study with a larger sample-size is needed before any firm conclusions on the pain reducing effect of PEMF can be drawn

The aim of this study was to report the incidence of arthrofibrosis of the knee and identify risk factors for its development following a fracture of the tibial plateau. We carried out a retrospective review of 186 patients (114 male, 72 female) with a fracture of the tibial plateau who underwent open reduction and internal fixation. Their mean age was 46.4 years (19 to 83) and the mean follow-up was16.0 months (6 to 80).

A total of 27 patients (14.5%) developed arthrofibrosis requiring a further intervention. Using multivariate regression analysis, the use of a provisional external fixator (odds ratio (OR) 4.63, 95% confidence interval (CI) 1.26 to 17.7, p = 0.021) was significantly associated with the development of arthrofibrosis. Similarly, the use of a continuous passive movement (CPM) machine was associated with significantly less development of arthrofibrosis (OR = 0.32, 95% CI 0.11 to 0.83, p = 0.024). The effect of time in an external fixator was found to be significant, with each extra day of external fixation increasing the odds of requiring manipulation under anaesthesia (MUA) or quadricepsplasty by 10% (OR = 1.10, p = 0.030). High-energy fracture, surgical approach, infection and use of tobacco were not associated with the development of arthrofibrosis. Patients with a successful MUA had significantly less time to MUA (mean 2.9 months; sd 1.25) than those with an unsuccessful MUA (mean 4.86 months; sd 2.61, p = 0.014). For those with limited movement, therefore, performing an MUA within three months of the injury may result in a better range of movement.

Based our results, CPM following operative fixation for a fracture of the tibial plateau may reduce the risk of the development of arthrofibrosis, particularly in patients who also undergo prolonged provisional external fixation.

Cite this article: Bone Joint J 2015;97-B:109–14.