Introduction
Primary hyperparathyroidism (PHPT) is the most common cause of hypercalcemia. In Western countries, the clinical profile of primary hyperparathyroidism has shifted from a symptomatic disease characterised by hypercalcemic symptoms, nephrolithiasis, overt bone disease and neuromuscular symptoms to a disease of asymptomatic hypercalcemia detected on routine biochemical screening. Majority of asymptomatic patients do not have disease progression, as evidenced by stable biochemical measures and BMD for up to a decade of observation. This then raises the question of if, and when, these asymptomatic patients should undergo surgery.
According to the 3 rd International Workshop on the Management of Asymptomatic Primary Hyperparathyroidism, surgery is recommended for those under 50 years old, serum calcium >0.25mmol/L above upper limit of normal, reduced creatinine clearance <60ml/min, T-score<- 2.5 at any site, previous fragility fracture and in individuals whom surveillance is not feasible.
Aims
To determine if patients with primary hyperparathyroidism were appropriately managed with parathyroid surgery according to international guidelines.

Objectives
• 1. To determine the percentage of patients who underwent parathyroidectomies for PHPT between 01/01/2010 – 01/10/2011 at Box Hill Hospital and Maroondah Hospital.
• 2.To assess if there is evidence that accepted clinical and biochemical criteria were being used to select for parathyroidectomy.
• 3.To determine the success rate and complications related to parathyroid surgery at these 2 hospital sites.
• 4.To assess whether there are predictors of increased risk of post-surgical complications
Methods
Retrospective audit of all patients with primary hyperparathyroidism presenting to Box Hill and Maroondah Hospital between 01/01/2010 and 01/10/2011.

Results
45.94% patients underwent parathyroid surgery in the 21 month study period. Patients who underwent surgery were significantly younger (64.57 years old vs 80.45, P<0.01) and had higher serum calcium levels (3.05 vs 2.90, P=0.01). Successful localization studies were more common in the surgical group but this was not statistically significant.
Older age, pre-op calcium and Vitamin D levels, pre-op bisphosphonate use were shown to be not statistically significant in increasing rates of post-op hypocalcemia. Success rate, defined as normalisation of serum calcium was achieved in 30 out of 34 (88.2%) patients. Post-operative complications include transient hypocalcemia requiring calcium supplementation (29.5%) and persistent hypercalcaemia post operation (11.8%). Only one third of our patinets had DEXA scans as part of their work up. 

Conclusion
Our study suggests that younger age and positive results of localization studies may have determined the decision to proceed to surgery rather than disease severity or complications.Patients with PHPT who meet the criteria for surgery should be referred for parathyroidectomy given the high success rate and low complication risk. Patients should have a bone mineral density performed as part of their work up as cross sectional studies show an increased rate of fractures among people with PHPT. Furthermore, surveillance with BMD every 1-2 years is recommended for patients who do not undergo parathyroidectomies.