Complete excision of the infrapatellar fat pad is associated with patellar tendon shortening after primary total knee arthroplasty.

BACKGROUND: Patella baja is a potentially disabling and difficult-to-treat complication following total knee arthroplasty (TKA). We investigated whether complete or partial excision of the fat pad has an effect on the length of the patellar tendon following TKA. METHODS: A retrospective review of patient radiographs was performed. One hundred and eleven consecutive patients who underwent primary TKA for osteoarthritis using the same components by two consultants were selected. Seventy-two patients underwent complete excision of the fat pad, whilst 39 had partial excision as per consultant practice. Patellar height was measured using the Caton-Deschamps Index (CDI) on immediate postoperative radiographs and at a minimum follow-up of 1 year. RESULTS: In the complete excision group, the mean CDI changed from 0.54 immediately postoperatively to 0.45 at a minimum follow-up of 1 year (p < 0.0001) indicating shortening of the patellar tendon, and eight patients reported anterior knee pain. The partial excision group's mean CDI changed from 0.76 to 0.75 (p = 0.231). An analysis of variance showed that the effect of complete fat pad excision on patella tendon length was significant, F(1, 109) = 15.273, p < 0.001. CONCLUSION: At a minimum follow-up of 1 year, the patellar tendon length shortened significantly in the group of patients with complete fat pad excision. With partial excision, there was no significant change in tendon length. Complete excision of the fat pad should therefore be avoided wherever possible in an attempt to avoid patella baja. LEVEL OF EVIDENCE: II.

Decision making for knee replacement: variation in treatment choice for late stage medial compartment osteoarthritis.

BACKGROUND: Patients with medial unicompartmental osteoarthritic disease of the knee requiring arthroplasty can be treated with either Total or Unicompartmental Knee Replacement (TKR or UKR). Currently, the decision to choose one operation over another is not well defined and may depend on the profile of the surgeon consulted. We tested the hypothesis that different surgeons will select different treatment for identical patients requiring knee replacement. METHOD: Four different surgeons, representing four different levels of expertise, made a forced choice decision of whether they would perform TKR or UKR based on radiographs alone and subsequent additional clinical information including gender and age, in 140 patients. Individual surgeon repeatability was tested by repeat assessment 3 months later. RESULTS: The knee surgeon from the UKR design centre would have performed a UKR in up to 88% of the patients. The remaining surgeons would have performed UKR in 29-48% of patients; a variation in decision making of up to 59%. Additional clinical information had little effect on decision making with surgeons maintaining their radiographic based choice in 80 to 87% of cases. The repeatability study showed high within surgeon consistency for treatment choice. CONCLUSION: Surgeons, given identical information, do not concur on treatment for patients with the same pathology. The decision making process appears heavily influenced by radiographic findings but individual surgeons are consistent with their own treatment choice. The study shows that consensus treatment for medial osteoarthritis of the knee remains in question.

Functional relevance of patellofemoral thickness before and after unicompartmental patellofemoral replacement.

The aim of this study was to assess the increase in the anterior height of the knee after unicompartmental patellofemoral replacement and the impact of this increase on the range of motion and function of the knee. Twenty-eight patients (34 knees) who underwent patellofemoral replacement with FPV(TM) prosthesis between 2005 and 2009 were identified and retrospectively analyzed using chart and radiological review. Trochlear height and patellar thickness were measured combined and compared pre and postoperatively. The range of movement and functional outcome scores after 6-12 months follow-up were noted. The effect of increased postoperative anterior-posterior height of the knee on the range of motion was studied. Postoperative mean range of flexion of the knee joint was 116°. The mean Oxford knee score was 21 points. The mean American Knee Society Knee Score was 80 points for pain and 61 points for function. The trochlear height and patellar thickness were increased by 3.5 and 2.5 mms respectively, resulting in average total increase of 6mm in the anterior-posterior height of the knee. We found no relationship between range of motion and function of the knee and the increase in the anterior-posterior height. We found a negative correlation between increase in the anterior-posterior height and preoperative anterior-posterior height. FPV patellofemoral replacement results in correct anatomical reconstruction of the trochlear height rather than 'overstuffing' of the patellofemoral joint. There is an increase in anterior-posterior height of the knee but this does not affect range of movement or clinical outcome.

Feeding 2-hydroxy-4-(methylthio)-butanoic acid to periparturient dairy cows improves milk production but not hepatic metabolism.

Forty-eight Holstein cows, entering second or later lactation, were utilized to determine the effects of 2-hydroxy-4-(methylthio)-butanoic acid (HMB) on milk production, hepatic lipid metabolism, and gluconeogenesis during the periparturient period. Cows were fed one of 3 diets as TMR starting 21 d before expected calving. These diets contained 0 (the basal diet), 0.09 (+HMB), or 0.18 (++HMB)% HMB. From parturition to 84 DIM, cows were fed diets that contained 0, 0.13, or 0.20% HMB. Prepartum and postpartum dry matter intakes were similar among cows fed the basal diet, +HMB and ++HMB. There was a quadratic effect on milk yield such that cows fed +HMB had the greatest milk yield; yields of milk by cows fed the basal diet and ++HMB were similar. This led to trends for increased yields of 3.5% fat-corrected milk and total solids when cows were fed +HMB. Percentages of fat, protein, and total solids in milk were not affected by treatment. Despite differences in milk yield, calculated energy balance was not affected by treatment. Plasma concentrations of NEFA, beta-hydroxybutyrate, and glucose were not different among treatments. Liver triglyceride content was similar among treatments on d 1 postpartum and was increased for cows consuming +HMB on d 21 postpartum compared with the other dietary treatments. Capacities for metabolism of [1-14C]palmitate by liver slices in vitro were not affected by treatment; however, conversion of [1-14C]propionate to CO2 and glucose decreased as the amount of HMB consumed by cows increased on d 21 postpartum. Cows consuming +HMB had greater days to first ovulation compared with cows consuming the basal diet and ++HMB as measured by plasma progesterone concentrations. These data suggest that adding HMB to low Met diets to achieve a predicted Met supply of approximately 2.3% of metabolizable protein supply is beneficial for increasing milk production but does not appear to benefit hepatic energy metabolism during early lactation.

Management of whiplash injuries presenting to accident and emergency departments in Wales.

OBJECTIVES: To assess the use of soft collars for whiplash injuries presenting to Welsh accident and emergency departments and compare with recommended treatment as suggested by other literature. METHODS: Questionnaires were sent to 76 full time accident and emergency staff across Wales inquiring into their management of soft tissue sprains/strains of the neck and soft collar use. RESULTS: The overall response rate was 74% (SHO 70%, registrar 65%, consultant 100%). Half of consultants and more than half of the middle grade and junior staff reported soft collar use in this condition. As required wear was most commonly recommended and instructions for use ranged from one day only to until the patient was pain free. CONCLUSION: The study recommends treatment protocols for whiplash injuries prescribing regular analgesia, early home exercises with the help of an advice sheet, and physiotherapy if symptoms persist.

'Fat fracture'--a physical sign mimicking tendon rupture.

The imaging techniques available to aid the diagnosis of ruptures of tendo Achillis, the rotator cuff and the tendon of tibialis posterior in rheumatoid patients are well described. However, ruptures of tendon or muscle at other sites are uncommon and may be overlooked. Diagnosis is often made by localised tenderness, swelling and a lack of active movement associated with a palpable defect. Clinical examination may be inconclusive and can be aided by imaging studies. We report two cases in which ruptures of a tendon were suspected, and ultrasound imaging demonstrated the palpable defect to be a cleavage plane in the subcutaneous fat--a 'fat fracture'.

Prosthesis displacement as a complication of reduction of a dislocated total hip arthroplasty.

Acute displacement at the cement-prosthesis interface of the femoral component of a hip arthroplasty that occurred as a consequence of attempted reduction of a dislocation is described. Although this complication is theoretically possible with a polished tapered stem design, it is previously unrecognized, and may be avoidable if fluoroscopic control is used during closed reduction of a dislocation.

MRI in the management of tibial plateau fractures.

Twenty-one consecutive patients with fractures of the tibial plateau were investigated by standard radiography and magnetic resonance imaging (MRI) before treatment. It was found that MRI was more accurate in determining the classification of the fracture, in the identification of previously 'occult' fracture lines, and in accurate measurement of displacement and depression of fragments. This resulted in a change in the classification of 10 fractures (47.6 per cent) and so a change in the management of four patients (19 per cent). In addition, MRI permits the reliable identification of associated intra- and periarticular soft tissue injuries pre-operatively for the first time in this group of injuries, seen to be present in 47.6 per cent of this series. This is higher than previously reported. No problems were encountered with the imaging technique, and in view of the significant effect on patient management, the authors now consider it to be the imaging method of choice.