Traditionally, periodic acid \200\223Schiff (PAS) staining of a duodenal biopsy speci- men has been the first-line diagnostic test (Fig. 30.2 ). The typical appearance is of foamy ma crophages containing numerous PAS-positive organisms within the lamina propria. PAS-positiv e cells can be found in any affected organ. However, PAS staining is non-specific and can a lso be seen with other infectious agents including Mycobacterium avium intracellulare , Cor ynebacterium , and Histoplasma . Immunohistochemistry using T.Whippelii -specific antibodie s improves histo- logical specificity and sensitivity. In addition, a polymerase chain reac tion (PCR)- based assay is now available in a few centers, but can be associated with false -positive detection in healthy individuals. Fig. 30.2 (See also Plate 14) Photomicrographs of the duodenal biopsy showing macrophages c ontaining PAS-positive granules. 177 CASE 30 3. How would you manage this condition? Whipple \200\231s disease is potentially fatal if left untreated but responds to antibiotic therapy. Current recommendations for the treatment of Whipple \200\231s disease com- prise induction therapy with intravenous antibiotics, commonly 14 days of ceftriax- one followed by continuation therapy with oral co-trimoxazole for 1 \200\2232 years. The response to tr eatment should be monitored closely as relapses are common, par- ticularly in CNS disease w hich is associated with a high rate of recurrence after apparently successful treatment. In view of the risk of relapsing CNS disease, cur- rent recommendations favor co-trimoxazole over penicillins as it has blood \200\223brain barrier penetration. Further reading Desnues B , Al Moussawi K , Fenollar F ( 2002 ). New insights into Whipple \200\231s diseas e and Tropheryma whipplei infections . Microbes Infect ; 12 : 1102 \200\223 10 . Pu chal X ( 20 02 ). Whipple \200\231s disease . Joint Bone Spine ; 69 : 133 \200\223 40 . 178 CASE HISTORIES IN RHEUMATOLOGY Case 31 A 28-year-old female runner presented with a 1-month history of right groin pain. She was a keen runner and ran competitively in marathons at a national level. Recently, she had incr eased her workload in preparation for a mountain challenge run. The pains were localized to her right groin and had come on insidiously but had gradually become worse over the preced ing month. At presentation, she was complaining of pain in the right groin on walking and o n any weight-bearing exercise. She denied any night pain. There was no history of an acute injury. She had sustained a right navicular stress fracture in the past which was treated conservat ively. She had been amenorrheic for 1 year and oligomenorrheic for 5 years prior to that. S he limited her intake of energy rich foods. She changed her running shoes every 300 \200 \223500 miles. On examination her BMI was 17 kg/m 2 . She had a limp due to pain on weight- bearing. There was no tenderness over the groin. Passive internal and external rotation of the hip exacer bated the pain only at the end range of movements. She had globaly good muscle strength aro und the hip joint. The DEXA scan showed T -scores of \200\2232.6 at the spine and \200\2232.8 at the hip. Th e MRI of the hip joint is shown in Fig. 31.1 . Fig. 31.1 MRI of the right hip. 179 CASE 31 Questions 1. What is the diagnosis? 2. What are the complications of this condition? 3. What other issues have been identified? 4. What other investigations would you request? 5. How would you treat this athlete? 180 CASE HISTORIES IN RHEUMATOLOGY Answers (a) (b) Fig. 31.2 (a) NOF stress fracture of the inferior surface on MRI (arrow). (b) NOF stress fr acture of superior surface on X-ray (arrowhead). 1. What is the diagnosis? The diagnosis is a stress fracture of the neck of the femur (NOF). Femoral neck stress frac tures can be classified as superior surface or inferior surface (Fig. 31.2 ). In this case the stress fracture is on the inferior surface (Fig. 31.2 ). NOF stress frac- tures are mor e commonly seen on the inferior surface (80 % ) than on the superior surface (20 % ). 2. What are the complications of this condition? NOF stress fractures are at high risk of progression to a complete displaced fracture with the possibility of avascular necrosis of the femoral head. Stress fractures of the superior surface are on the tension side of the femur; hence they are less stable and have a higher tendency to progress to a full fracture. Inferior surface fractures are on the compression side of the femur and are more stable. 3. What other issues have been identified? This athlete is noted to have a disordered eating pattern and amenorrhea, and she is also o steoporotic. This triad of conditions is termed the \200\230female athlete triad \200\231. The process is driven by an energy imbalance due to increased expenditure during exercise together with inadequate energy intake due to disordered eating patterns. This results in a low BMI and also shutting down of the hypothalamic \200\223pituitary axis, resulting in me nstrual disturbance. This in turn affects bone health and predisposes the athlete to stress fractures. 181 CASE 31 4. What other investigations would you request? Further investigations should be carried out to investigate the metabolic bone issues and t he amenorrhoea. Blood tests should include full blood count, bone profile, thyroid function , renal function, liver function, sex hormone profile, and vitamin D levels, and exclusion of malabsorption with endomysial or tissue transglutaminase antibodies. Prior to returning to sporting activities a formal biomechanical assessment should be considered, involving as sessment of the athlete \200\231s walking and running biomechanics. This would involve gait analysis using motion detectors and high-speed cameras in a gait laboratory. 5. How would you treat this athlete? There are two main issues that need to be addressed. Treatment of the stress fracture Treatment is either conservative or surgical. Conservative methods are favored for NOF stress fractures of the inferior surface. Conservative treatme nt includes immediate non-weight-bearing rest with the use of crutches. The non-weight bear ing period is usually guided by the patient \200\231s symptoms, but should last for at leas t 4 \200\2236 weeks. This is followed by a gradual introduction of activities, with a retur n to sport taking approx- imately 6 months. Surgical management is usually favored for the treatment of NOF stress fractures of the superior surface. Addressing the female athlete triad and associated issues This is paramount to prevent furt her stress fractures. A multidisciplinary team approach with input from a sport and exercis e medicine physician, a nutritionist, a psychologist and a coach is important. A considerab le amount of time should be spent educating the athlete on the issues surrounding the femal e athlete triad and developing strategies to address these. The key would be to address the energy imbalance by increasing energy intake, optimizing training sessions, and ensuring a dequate recovery time between training sessions. There could be some overlap with more seri ous eating disorders such as anorexia nervosa and bulimia. Hence, where appropriate, a psyc hiatrist may be added to the multidisciplinary team. Further reading Birch K ( 2005 ). Female athlete triad . In: Whyte G , Harries M , Williams C . ABC of Spor ts and Exercise Medicine ( 3rd edn). Oxford : Blackwell; pp. 50 \200\223 3 . Brukner P, Khan K ( 2006 ). Clinical Sports Medicine ( 3rd edn). Sydney : McGraw-Hill .