Outcomes of combined tibial tuberosity transfer and medial patellofemoral ligament reconstruction for recurrent patellar instability.

Patellofemoral instability is multifactorial and is associated with pathomechanics secondary to anatomical variance. Surgical management of this problem must be tailored to each patient and a thorough clinical and radiological assessment of the anatomical alignment should be carried out pre-operatively. The aim of this study is to assess the role of medial patellofemoral ligament reconstruction combined with tibial tuberosity transfer in patients with increased tibial tuberosity to trochlear groove (TT-TG) distance. Twenty-four patients (27 knees) over 2-years were operated on by a single surgeon, with standardised post-operative rehabilitation and follow up. Mean follow up was 31-months. Two patients had problems with recurrent instability, 1 had a -traumatic re-dislocation at 2 years and a total of 4 required further operation for complications. Mean post--operative Kujala scores were 87.4 (SD 9.8). Combined medial patellofemoral ligament reconstruction and tibial tuberosity transfer is an appropriate treatment for patients with increased TT-TG distance.

Impaired lymphatic cerebrospinal fluid absorption in a rat model of kaolin-induced communicating hydrocephalus.

It has been assumed that the pathogenesis of hydrocephalus includes a cerebrospinal fluid (CSF) absorption deficit. Because a significant portion of CSF absorption occurs into extracranial lymphatics located in the olfactory turbinates, the purpose of this study was to determine whether CSF transport was compromised at this location in a kaolin-induced communicating (extraventricular) hydrocephalus model in rats. Under 1-3% halothane anesthesia, kaolin (n = 10) or saline (n = 9) was introduced into the basal cisterns of Sprague-Dawley rats, and the development of hydrocephalus was assessed 1 wk later using MRI. After injection of human serum albumin ((125)I-HSA) into a lateral ventricle, the tracer enrichment in the olfactory turbinates 30 min postinjection provided an estimate of CSF transport through the cribriform plate into nasal lymphatics. Lateral ventricular volumes in the kaolin group (0.073 +/- 0.014 ml) were significantly greater than those in the saline-injected animals (0.016 +/- 0.001 ml; P = 0.0014). The CSF tracer enrichment in the olfactory turbinates (expressed as percent injected/g tissue) in the kaolin rats averaged 0.99 +/- 0.39 and was significantly lower than that measured in the saline controls (5.86 +/- 0.32; P < 0.00001). The largest degree of ventriculomegaly was associated with the lowest levels of lymphatic CSF uptake with lateral ventricular expansion occurring only when almost all of the lymphatic CSF transport capacity had been compromised. We conclude that lymphatic CSF absorption is impaired in a kaolin-communicating hydrocephalus model and that the degree of this impediment may contribute to the severity of the induced disease.

Impact of ageing on lymphatic cerebrospinal fluid absorption in the rat.

Several parameters associated with the cerebrospinal fluid (CSF) system show a change in the later stages of life, including elevated CSF outflow resistance. The latter implies a CSF absorption deficit. As a significant portion of CSF absorption occurs into extracranial lymphatic vessels located in the olfactory turbinates, the purpose of this study was to determine whether any age-related impediments to CSF absorption existed at this location. In previous studies, we observed rapid movement of the CSF tracer into the olfactory turbinates in young rats (peaking 30 min after injection), with the concentration of the tracer being much higher in the turbinates than in any other tissue measured. In the study reported here, (125)I-human serum albumin was injected into the lateral ventricles of 3-, 6-, 12- and 19-month-old Fisher 344 rats. The animals were sacrificed at various times after injection of the radioactive tracer, and appropriate tissue samples were extracted. At 30 min post injection, the average tracer values expressed as per cent injected/g tissue were 6.68 +/- 0.42 (n = 9, 3 months), 4.78 +/- 0.67 (n = 9, 6 months), 2.49 +/- 0.31 (n = 9, 12 months) and 2.42 +/- 0.72 (n = 9, 19 months). We conclude that lymphatic CSF transport declines significantly with age. In concert with the known drop in CSF formation, the reduction in lymphatic CSF absorption may contribute to a decrease in CSF turnover in the elderly.