Ganz peri-acetabular osteotomy is commonly used to treat symptomatic hip dysplasia. It aims to increase the load bearing contact area of the hip to reduce the risk of subsequent osteoarthritis. In this study we assess the radiographic and clinical results of the procedure since its introduction to our unit. All patients undergoing Ganz osteotomies at our unit were followed up prospectively. Data collected included patient demographics and pre- and post-operative functional scores (Harris and Non-arthritic hip scores). In addition, acetabular correction was evaluated on pre-and post-operative radiographs (using Centre-Edge angle and Tonnis angle). Complications were also noted. Overall 50 procedures were performed between 2007 and 2013 with median follow-up of 3 years (1 – 7 years). The majority of patients (90%) were female. Average age at time of surgery was 29 years (16–49). There were significant improvements in pre- and post-operative median functional scores (Modified Harris Hip Score = 49 versus 64, p=0.001), Non-arthritic Hip Score = 42 versus 56, p=0.007). Median Centre Edge Angle improved from 16 degrees pre-operatively (range = 7–31 degrees) to 30 degrees post-operatively (18–33) degrees), p<0.0001. Similarly, pre-operative Tonnis angle improved from 18 degrees (9–38) to 7 degrees (2–14), p<0.0001. Five patients developed post-operative complications: 2 superficial wound infection, 1deep infection requiring hip washout and antibiotic treatment and 2 patients subsequently requiring total hip replacements. We have shown that the Ganz peri-acetabular osteotomy can be effective for the treatment of painful hip dysplasia improving both functional and radiographic outcomes. However, patient selection is a key factor

This case series highlights the use of the Ganz approach and surgical dislocation for excision of fibrous dysplasia of the femoral neck, pigmented villonodular synovitis and synovial chrondromatosis of the hip, which has never been described for use with all three tumours together. These are rare benign tumours, which were found incidentally and required excision. We demonstrate that it is possible to obtain excellent exposure of the femoral neck, head and acetabulum allowing easy inspection, exploration and debridement of these three tumours of the hip

Femoroacetabular impingement (FAI) is the result of abnormal contact/impingement of the femoral head-neck junction and acetabulum during motion. This can be corrected by surgical dislocation (using Ganz's trochanteric osteotomy) and femoral osteochondroplasty +/− acetabular rim resection. Our study aimed to assess the improvement in hip scores following open osteochondroplasty to predict outcomes based on patient characteristics. This was a retrospective case note analysis of a single surgeon case series over a 4 year period. Inclusion criteria were open osteochondroplasty, complete pre- and post-op hip scores available), Tonnis osteoarthritis grade 0 or 1, with 1 year followup. Data was extracted from electronic and paper case notes for pre- and post-op Modified Harris Hip Scores (MHHS), Non-arthritis Hip Scores (NAHS) and SF-12 general satisfaction scores, as well as baseline patient demographics. Two independent observers used the PACS radiology system to examine x-rays and MRI. SPSS version 19 was used for statistical analysis. 42 patients met the inclusion criteria. There was an overall improvement in hip scores after the procedure. Mean pre-op scores were MHHS 52.5, NAHS 44.0, SF-12 32.1. Mean post-op scores were MHHS 66.1, NAHS 58.7, SF-12 36.4. Therefore mean improvements were seen in MHHS (13.6), NAHS (14.7) and SF-12 (4.3), all significant at p<0.005 when paired t-test was used for analysis. Pearson correlation for subgroup analysis showed no significant correlation of scores with age, centre-edge angle or alpha angles. Furthermore, no significant difference was seen between males and females (independent t test). Open osteochondroplasty improves symptoms and function based on patient reported outcome measures. Although the mean scores improved, some patients’ scores deteriorated. We have not identified any statistically significant predictors of outcome, and therefore patient selection remains unclear

Recently, femoroacetabular impingement has been recognised as a cause of early osteoarthritis. There are two mechanisms of impingement: 1) cam impingement caused by a non-spherical head and 2) pincer impingement caused by excessive acetabular cover. We hypothesised that both mechanisms result in different patterns of articular damage. Of 302 analysed hips only 26 had an isolated cam and 16 an isolated pincer impingement. Cam impingement caused damage to the anterosuperior acetabular cartilage with separation between the labrum and cartilage. During flexion, the cartilage was sheared off the bone by the non-spherical femoral head while the labrum remained untouched. In pincer impingement, the cartilage damage was located circumferentially and included only a narrow strip. During movement the labrum is crushed between the acetabular rim and the femoral neck causing degeneration and ossification.

Both cam and pincer impingement lead to osteoarthritis of the hip. Labral damage indicates ongoing impingement and rarely occurs alone.

In this prospective, randomised study, we have compared the wear rate of cemented, acetabular polyethylene cups articulating with either a 22 mm or a 32 mm cobalt-chromium head. We evaluated 89 patients who had a total of 484 radiographs. The mean follow-up period was 71.4 months (SD 29.1). All the radiographs were digitised and electronically measured.

The linear wear rate was significantly higher during the first two years and decreased after this period to a constant value. We suggest that this is partly due to a ‘run-in’ process caused by irregularities between surfaces of the cup and head and an initial plastic deformation of the polyethylene. The mean volumetric wear was 120.3 mm³/year for the 32 mm head, which was significantly higher than the 41.5 mm³/year for the 22 mm heads. The mean linear wear rate was not significantly different. We were, however, unable to find radiological signs of osteolysis in the patients who had higher wear rates.

We used laser Doppler flowmetry (LDF) with a high energy (20 mW) laser to measure perfusion of the femoral head intraoperatively in 32 hips. The surgical procedure was joint debridement requiring dislocation or subluxation of the hip. The laser probe was placed within the anterosuperior quadrant of the femoral head. Blood flow was monitored in specific positions of the hip before and after dislocation or subluxation.

With the femoral head reduced, external rotation, both in extension and flexion, caused a reduction of blood flow. During subluxation or dislocation, it was impaired when the posterosuperior femoral neck was allowed to rest on the posterior acetabular rim. A pulsatile signal returned when the hip was reduced, or was taken out of extreme positions when dislocated. After the final reduction, the signal amplitudes were first slightly lower (12%) compared with the initial value but tended to be restored to the initial levels within 30 minutes.

Most of the changes in the signal can be explained by compromise of the extraosseous branches of the medial femoral circumflex artery and are reversible. Our study shows that LDF provides proof for the clinical observation that perfusion of the femoral head is maintained after dislocation if specific surgical precautions are followed.

Free patellar tendon grafts used for the intra-articular replacement of ruptured anterior cruciate ligaments (ACL) lack perfusion at the time of implantation. The central core of the graft undergoes a process of ischaemic necrosis which may result in failure. Early reperfusion of the graft may diminish the extent of this process.

We assessed the role of peritendinous connective tissue in the revascularisation of the patellar tendon graft from the day of implantation up to 24 days in a murine model using intravital microscopy. The peritendinous connective-tissue envelope of the graft was either completely removed, partially removed or not stripped before implantation into dorsal skinfold chambers of recipient mice.

Initial revascularisation of the grafts with preserved peritendinous connective tissues began after two days. The process was delayed by five to six times in completely stripped patellar tendons (p < 0.05). Only grafts with preserved connective tissues showed high viability whereas those which were completely stripped appeared to be subvital.

The presence of peritendinous connective tissues accelerates the revascularisation of free patellar tendon grafts.