Introduction. Bony deformities in the hip that cause femoroacetabular impingement (FAI) can be resected in order to delay the onset of osteoarthritis and improve hip range of motion. However, achieving accurate osteoplasty arthroscopically is challenging because the narrow hip joint capsule limits field of view. Recently, image-based navigation using a preoperative plan has been shown to improve the accuracy of femoral bone surfaces following arthroscopic osteoplasty for FAI. The current standard for intraoperative monitoring, 3D x-ray fluoroscopy, is accurate at the initial registration step to within 0.8±0.5mm but involves radiation. Intraoperative 3D ultrasound (US) is a promising radiation-free alternative for providing real-time visual feedback during FAI osteoplasty. The objective was to determine if intraoperative 3D US of the femoral head/neck region can be registered to a CT-based preoperative plan with comparable accuracy to fluoroscopic navigation in order to visualise progress during arthroscopic FAI osteoplasty. Methods. The experiment used a plastic femur model that had a cam deformity on the femoral head/neck. Thirty metal fiducial markers were placed on the US-accessible anterior and lateral surfaces of the femur. A CT image was acquired and reconstructed, then used to develop a preoperative plan for resection of the cam deformity. Twenty-two sets of 3D US data were then gathered from the phantom using a clinical ultrasound machine and 3D transducer while the phantom was submerged in water. US surfaces from the anterior/lateral regions of the femur were extracted using a recently proposed image processing algorithm. Fiducials in the US volume were manually registered to corresponding CT fiducials to provide a reference standard registration. The reference standard fiducial registration error (FRE) was measured as the average distance between corresponding fiducials. After fiducial-based registration, each US surface was randomly misaligned and re-registered using a coherent point-drift algorithm. The resulting surface registration error (SRE) was measured using average distance between US and CT surfaces. Finally, a plastic model of the preoperative cam deformity resection plan was 3D-printed to represent the postoperative femur. Five US scans were acquired of the postoperative model near the femoral head/neck. Each US scan was initialised for 20 trials using three reference points, and then registered using coherent point drift. Surgical outcome accuracy was reported using final surface registration error (fSRE). Results. The reference standard FRE was 0.41±0.19mm. The distance between surfaces following misalignment and re-registration for all 2200 automated registration trials was similarly small (SRE = 0.31±0.04mm) and well below the required clinical limit. Lastly, the postoperative model was accurately registered to corresponding US scans (fSRE = 0.58±0.07mm). Qualitative visualisation showed good surface matching following US to CT registration. Conclusion. Initial registration between intraoperative 3D US and preoperative CT is critical for accurate visualisation of surgical progress during FAI osteoplasty. Given spatial initialisation, the achievable registration accuracy of 3D US to CT is 0.31±0.04mm (SRE) which is well within the fluoroscopy standard, 0.8±0.5mm. The results suggest strong potential for ultrasound to guide computer-assisted arthroscopic FAI osteoplasty

When patients present at an early age with osteoarthritis of the hip, there is usually an underlying predisposing cause. In men, a common cause is femoroacetabular impingement (FAI). This is evident as anterior neck osteophytes, with retroversion and varus alignment of the femoral head, most likely the result of subclinical slipped capital femoral epiphysis. The resulting femoroacetabular cam impingement causes degenerative osteoarthritis (OA) of the hip, at an earlier age than primary OA. Patients present in their 40s and 50s with advanced arthritis, and are faced with the prospect of a total hip arthroplasty. Women may experience this as well, but may present with early hip arthritis as a result of subclinical dysplasia or pincer FAI more often than their male counterparts. Hip resurfacing has several advantages over traditional total hip replacement for younger patients, especially men. These include bone preservation, less dislocation, thigh pain or leg length inequality, easier return to athletics, and easy revision on the femoral side. It is indicated in young, active patients. The resurfacing procedure realigns the femoral head on the native and resurfaces the arthritic joint. Anterior neck osteoplasty is performed. Head retroversion is corrected. This restores deep flexion, and eliminates forced external rotation in flexion. Hip resurfacing can be done through either an anterior or posterior approach, although the anterior approach gives easier access to the anterior femoral neck, and preserves the blood supply to the head. This may help prevent femoral neck fractures and late head collapse

There are a number of progressive conditions that afflict the hip and result in degenerative arthritis. Along the path of progression of the disease and prior to the development of arthritis, some of these conditions may be treatable by joint preservation procedures. Periacetabular osteotomy for developmental dysplasia of the hip (DDH), femoroacetabular osteoplasty for femoroacetabular impingement (FAI), and a variety of surgical procedures for management of early osteonecrosis of the femoral head are some examples of joint preservation of the hip. DDH is characterised by abnormal development of the acetabulum and the proximal femur that leads to suboptimal contact of the articular surfaces and the resultant increase in joint reaction forces. FAI is a condition characterised by an abnormal contact between the femoral neck and the acetabular rim. FAI is believed to exist when a triad of signs (abnormal alpha angle, labral tear, and chondral lesion) can be identified. The question that remains is whether joint preservation procedures are able to avert the need for arthroplasty or just an intervention along the natural path of progression of the hip disease. There is an interesting study that followed 628 infants born in a Navajo reservation, including 8 infants with severe dysplasia, for 35 years. None of the children with DDH had surgical treatment and all had developed severe arthritis in the interim. The latter study and a few other natural history studies have shown that the lack of administration of surgical treatment to patients with symptomatic DDH results in accelerated arthritis. The situation is not so clear with FAI. Some believe that FAI is a pre-arthritic condition and surgical treatment is only effective in addressing the symptoms and does not delay or defer an arthroplasty. While others believe that restoration of the normal mechanical environment to the hip of FAI patients, by removing the abnormal contact and repair of the labrum, is likely to change the natural history of the disease and at minimum delay the need for an arthroplasty. There is a need for natural history studies or case series to settle the latter controversy

Purpose:. Despite advances in limb reconstruction, there are still a number of young patients who require trans-tibial amputation. Amputation osteoplasty is a technique described by Ertl to enhance rehabilitation after trans-tibial amputation. The purpose of the present study was to evaluate the results of the original Ertl procedure in skeletally immature patients, and to assess whether use of this procedure would result in a diminished incidence of bony overgrowth. Methods:. Four consecutive patients (five amputations) treated between January 2005 and June 2008 were reviewed. Clinical evaluation consisted of completion of the prosthesis evaluation questionnaire (PEQ) and physical examination. Radiographic analysis was performed to evaluate bone-bridge healing, bone overgrowth and the medial proximal tibial angle (MPTA). Results:. The best mean PEQ result in the Question section was 91.8 (Range 74–100) for ‘Well being’ and the worst mean score was 66.6 (Range 50–78) for the sub-section ‘Residual limb health’. Examination of the residual limbs revealed no bursae were present and all knees were stable with full range of movement. All bony bridges united at an average age of 1.7 months (Range 1–2). One case required stump revision for bony overgrowth, and one case developed asymptomatic mild genu varum. Conclusions:. In this series, the original Ertl osteomyoplasty shows good functional and prosthetic use with only one bony overgrowth requiring revision surgery

Purpose. Surgical dislocation is useful for assessing and treating proximal femoral hip deformities. Legg-Calv Perthes disease (LCPD) causes proximal femoral growth deformity, resulting in reduced femoral head-neck offset and femoracetabular incongruity. The purpose of this study was to demonstrate the efficacy and report the short-term results of surgical hip dislocation for the treatment of adolescents with healed LCPD. Method. This retrospective review included 29 adolescents [19 males and 10 females, age 17 (range nine-35)] with LCPD, who underwent surgical hip dislocation between January 2001 and December 2009. All subjects had a clear diagnosis of LCPD, pre and postoperative WOMAC scores and at least one year of clinical and radiographic follow up. In addition to surgical dislocation, all patients underwent femoral head-neck osteoplasty, 21 underwent relative femoral neck lengthening and trochanteric transfer, 12 underwent intertrochanteric osteotomy and seven had labral debridement. The average follow-up was three years from the time of surgical intervention. Results. Postoperative WOMAC scores improved globally for pain, stiffness and function (p<0.0001, p<0.0004 and p<0.0009 respectively). Eight patients required additional surgical procedures after surgical dislocation (one periacetabular osteotomy, one flexion intertrochanteric osteotomy, one arthrotomy, five arthroscopies with labral/cartilage debridement. Three patients underwent total hip arthroplasties during the follow-up period and were considered failures. Two of the 29 patients experienced superficial wound complications. Conclusion. Surgical dislocation is an effective technique for the treatment of proximal femur deformity associated with LCPD. In the short-term, patients experience improved symptoms and function from this procedure

Introduction. Femoroacetabular impingement (FAI) causes anterior hip pain, labral tears and damage to the articular cartilage leading to early osteoarthritis of the hip. Surgical hip dislocation and osteoplasty of the femoral neck and acetabular rim is a technique pioneered by the Bernese group for the treatment of FAI. We present and discuss our results of this technique. Methods. Functional outcome was measured in hips with over 12 month follow-up using the Oxford hip and McCarthy non-arthritic hip scores pre- and post-operatively. Results. From March 2003 to December 2005, 79 hips underwent surgical hip dislocation for treatment of FAI. Ten were skeletally immature and excluded. In 16 hips, grade 4 osteoarthritis was present in greater than 10 × 10mm regions after reshaping of the abnormal anatomy. In these cases, hip resurfacing was performed. Of the 53 hips preserved (average age 37(17-65)), 35 had the labrum detached, debrided and reattached using bone anchors, 32 underwent recession of the acetabular rim at the site of impingement, 21 had chondral ‘carpet’ flaps debrided, 5 had removal of medial osteophytes, 7 had labral and/or bony cysts excised and grafted and 1 underwent an osteochondral graft. In 5 hips osteoarthritis progressed requiring hip resurfacing at an average of 8 months. Oxford Hip Score improved from an average 32 (range 13-59) to 23 (12-45) and McCarthy hip score from 50 (19-76) to 63 (28-79) in the preserved hips at an average 20 months following surgery (range 12-38 months). Conclusion. The early results of surgical hip dislocation are encouraging. The open procedure has distinct advantages compared to arthroscopy enabling a wider range of lesions to be treated. Careful patient selection is important in order to exclude patients with hip osteoarthritis. Long-term follow-up is required to see if this technique prevents the natural progression to osteoarthritis

Femoroacetabular impingement is defined as abnormal abutment between the femoral head, or the femoral head-neck junction, and the acetabulum. It is now established that FAI is a major etiological factor in the development of osteoarthritis (OA) of the hip. FAI is increasingly recognized as a cause of hip pain in young active individuals. Clinical features of FAI include pain in the groin but this may also be felt in the gluteal region, trochanteric region, or in the thigh. Symptoms most commonly begin as an intermittent discomfort, often during or following periods of repetitive hip motion e.g. running, walking, progressing to more constant and intense pain. Stiffness is common, with reductions in the range of hip flexion, and internal rotation in particular. Patients may also complain of clicking, popping, or snapping sensations in the affected hip. Operative treatment of FAI is principally aimed at removing cam lesions and increasing femoral head-neck offset (osteochondroplasty), and treating associated soft tissue lesions such as labral tears. Acetabular recession with labral reattachment is increasingly used for pincers lesions but great care is needed to ensure that the overall coverage of the hip is not reduced. As proficiency with arthroscopic techniques has improved, arthroscopic osteochondroplasty and labral debridement/repair has become increasingly popular for the treatment for FAI, with promising functional results in a range of studies. 150 consecutive patients who underwent hip arthroscopy for CAM type FAI with minimum 1 year follow up were prospectively studied. Patient satisfaction, non-arthritic hip score, re-operations and conversion to arthroplasty were analysed. There were a total of 90 males and 60 females. The average age group was 32 years (27 to 46 years). All patients underwent osteoplasty of the CAM lesion and stabilisation/ repair of the labral tears. A comparison of pre procedure non arthritic hip scores with the scores at latest follow up (minimum 1 year, maximum 3 years) showed a significant improvement (56 vs 86; p <0.01). There were 2 re operations for unresolved symptoms and 1 conversion to arthroplasty for continued pain associated with significant loss of articular cartilage. Perineal numbness was noted in 9 patients all of which resolved. No other major complications were noted in this series. Hip impingement symptoms resolved in all cases and a good (20 %) to excellent (75%) outcome was reported. Arthroscopic management of CAM type FAI is associated with subjective and objective improvement in hip function at early follow up. Longer follow-up is necessary to analyse the ability of this procedure to arrest progression of degenerative hip disease