Gluteal muscle contracture (GMC), a debilitating disease, exists all over the globe but it is much more prevalent in China. Patients typically present with abduction and external rotation of the hip and are unable to bring both the knees together while squatting. Multiple etiologies have been postulated, the commonest being repeated intramuscular injection into the buttocks. The disease is diagnosed primarily by clinical features but radiological features are necessary for the exclusion of other pathological conditions. Non-operative treatment with physiotherapy can be tried before surgery is considered but it usually fails. Different surgical techniques have been described and claimed to have a better outcome of one over another but controversy still exists. Based on published literatures, the clinical outcome is exceptionally good in all established methods of surgery. However, endoscopic surgery is superior to conventional open surgery in terms of cosmetic outcome with fewer complications. Nevertheless, its use has been limited by lack of adequate knowledge, instrumentations, and some inherent limitations. Above all, post-operative rehabilitation plays a key role in better outcome, which however should be started gradually.

BackgroundGluteal muscle contracture (GMC), a debilitating disease, usually starts in early childhood after variable dose of injections around the buttock, if left untreated it worsens gradually and persists throughout the life. Because the disease mostly affects adolescents and adults, there is always an aesthetic concerns. Purposeof the study was to introduce the arthroscopic F and C method of GMC release, and to compare its clinical efficiency with conventional open surgery in terms of clinical outcome, rate of complications, patient’s satisfactions, and recurrence.MethodsBetween Jan 2013 and July 2015, 75 patients received an arthroscopic release with F and C release method and 71 patients received conventional open release of GMC. Primary surgeries in 16 years or older patients were included in the study. Two groups were compared clinically using Hip Outcome Scores – Activities of Daily Living Subscale (HOS-ADL), Hip Outcome Scores – Sports Subscale (HOS-Sports), Visual Analogue Scale (VAS), and Ye et al. evaluation criteria.ResultsNo statistically significant differences were observed in Hip Outcome Scores – Activities of Daily Living Subscale (HOS-ADL) (P = 0.078), Hip Outcome Scores – Sports Subscale (HOS-Sports) (P = 0.340), and Visual Analogue Scale (VAS) (P = 0.524) between the two groups. 74 (98.7%) patients in the arthroscopic surgery group had good to excellent results, whereas 69 (97.1%) patients in the conventional open surgery group had good to excellent results (P = 0.727). No statistically significant difference was observed in recurrence rate (P = 0.612). Statistically significant differences were observed in incision length, use of post-operative analgesia, post-operative off-bed activity, and hospital stay. Complications were significantly higher in the conventional open surgery group (n = 21) than in the arthroscopic surgery group (n = 10) (P = 0.016). More importantly, cosmetic satisfaction was 100% in arthroscopic release group, whereas only 71% had cosmetic satisfaction in conventional open surgery group (P < 0.001).ConclusionBoth, arthroscopic surgery and conventional open surgery, are highly effective tools for the GMC release in adolescent and adult patients. Arthroscopic GMC release with F and C method allows precise and selective release of contracture bands with small surgical trauma resulting fewer complications, high cosmetic satisfaction and minimal recurrence.

ObjectivesTo evaluate the diagnostic performance of different mathematical models and different b-value ranges of diffusion-weighted imaging (DWI) in peripheral zone prostate cancer (PZ PCa) detection.MethodsFifty-six patients with histologically proven PZ PCa who underwent DWI-magnetic resonance imaging (MRI) using 21 b-values (0–4500 s/mm2) were included. The mean signal intensities of the regions of interest (ROIs) placed in benign PZs and cancerous tissues on DWI images were fitted using mono-exponential, bi-exponential, stretched-exponential, and kurtosis models. The b-values were divided into four ranges: 0–1000, 0–2000, 0–3200, and 0–4500 s/mm2, grouped as A, B, C, and D, respectively. ADC, , D*, f, DDC, α, Dapp, and Kapp were estimated for each group. The adjusted coefficient of determination (R2) was calculated to measure goodness-of-fit. Receiver operating characteristic curve analysis was performed to evaluate the diagnostic performance of the parameters.ResultsAll parameters except D* showed significant differences between cancerous tissues and benign PZs in each group. The area under the curve values (AUCs) of ADC were comparable in groups C and D (p = 0.980) and were significantly higher than those in groups A and B (p< 0.05 for all). The AUCs of ADC and Kapp in groups B and C were similar (p = 0.07 and p = 0.954), and were significantly higher than the other parameters (p< 0.001 for all). The AUCs of ADC in group D was slightly higher than Kapp (p = 0.002), and both were significantly higher than the other parameters (p< 0.001 for all).ConclusionsADC derived from conventional mono-exponential high b-value (3200 s/mm2) models is an optimal parameter for PZ PCa detection.