Pilonidal disease is a disease of young people, usually men, which can result in an abscess, draining sinus tracts, and moderate debility for some. It probably results from hair penetration beneath the skin, for reasons that are not totally clear. Therapy should be simple, inflict minimal pain, have a short hospitalization, have a low recurrence rate, require minimal wound care, and allow rapid return to normal activity. No treatment meets all these ideal goals. Therefore, starting with a simple treatment and progressing to other treatments if failure occurs despite meticulous wound care and hair shaving is the logical approach. Table 1 depicts treatments from simple to more complex.

Despite the associated morbidity with continent ileostomy surgery, long-term results and quality of life were encouraging. Continent ileostomy may be offered as an attractive long-term option to select patients whose only alternative is an end ileostomy.

Repeat IPAA can often salvage pelvic pouches in patients with MUC who suffer major chronic perianastomotic and pelvic sepsis. Patients who had successful repeat IPAA surgery often report functional problems but would still choose to have the surgery again. For patients with CD, ultimate pouch excision or fecal diversion have been required in 40% indicating a guarded prognosis for these patients. Data on the success of the procedure for patients with indeterminate colitis and familial adenomatous polyposis were inconclusive because of small sample sizes.

Computer algorithms are proposed for the estimation of wear appearing in artificial hip joints using finite element analysis based on the modified Archard's wear law, contact features and an analogue wear process. A pin-on-disk plate experiment is reconstructed to assess the efficiency and validity of the algorithms proposed here. Through the successful verification of wear depth and volume loss of the pin-on-disk plate as well as the artificial hip joint, the current algorithms provide significant agreement with experiments, clinical measurements and numerical calculations and are shown to be both valid and feasible. Further investigation into the effect of femoral heads with various sizes suggests that the larger femoral head may induce larger wear volume but gives a smaller wear depth and that wear depth and volume loss are apparently nonlinearly related to the femoral head diameter. It is shown that the current algorithms are useful and helpful in understanding wear behavior for alternative or new designs of artificial hip joints and even for other analogous structures.

The CUSUM method was a useful tool for objectively measuring performance during the learning phase of IPAA surgery. With adequate training, supervision, and monitoring, the learning curve in IPAA surgery may be reduced even further.