Mechanoreceptors of the posterior cruciate ligament.

The mechanical role of the anterior and posterior cruciate ligaments in the passive and functional stability of the knee joint has been well documented. Both these knee joint ligaments contain Ruffini, Pacinian, Golgi and free nerve endings with different capabilities of providing the central nervous system with information regarding movement and position as well as chemical events. The posterior cruciate ligament provides 95% of the restraining force to a posterior tibial displacement, is significantly stronger than the other knee ligaments, and sensory nerve endings are located in the tibia and femoral bone insertions. This report aims to review the anatomy and physiology of the various mechanoreceptors of the posterior cruciate ligament, placing special emphasis on their role in knee joint stability. It concludes that the posterior crude ligament may not only serve as a 'mechanical stabilizer' of the knee joint, but also probably has an important 'sensory function' that should be taken into account when dealing with injuries to it.

Revision arthroscopic partial meniscectomy of the knee. A retrospective review.

The aim in this study was to find out if there were any revision operations in patients who underwent an arthroscopic partial meniscectomy and we attempted to identify the factor(s) that may be associated with the need for that revision. We reviewed 1,603 patients who underwent an arthroscopic partial meniscectomy, and 16 cases of revision were identified (rate 1%). Nine factors were analysed: age, sex, affected knee, affected meniscus, private or National Health Service (NHS) patient, symptoms prior to the most recent meniscectomy, type of tear, history of re-injury and the progression of Outerbridge changes to the articular surfaces. There was a significant risk for a revision meniscectomy in patients with horizontal/partial thickness tears compared to flap tears. No additional factor analysed was significantly associated with a revision procedure.

Intra-articular morphine and postoperative analgesia after knee arthroscopy.

The aim of this study was to evaluate the postoperative analgesic effect of intra-articular administration of a low- and a high-dose morphine solution after knee arthroscopy. Thirty patients who underwent diagnostic arthroscopy or arthroscopic meniscectomy were allocated in three groups. At the end of the arthroscopic procedure patients in Group A received intra-articularly 20 ml normal saline (N/S), Group B received 5 mg morphine in 20 ml N/S and Group C received 15 mg morphine in 20 ml N/S. The postoperative pain was assessed using a visual analogue scale for 24 h, while all the patients stayed at hospital. Side effects from the central action of opioids were not detected. Although the pain scores in the group of low-dose morphine were lower than in the control group, we failed to detect any significant differences in pain scores among the three groups. There was evidence that a high-dose can cause hyperalgesia.