Pincer deformities are involved in the genesis of femoro-acetabular impingement (FAI). Radiographic patterns suggestive of pincer deformities are common among general population. Prevalence of the pincer deformities among general population may be overestimated if only plain radiographs are considered. Pincer deformities (coxa profunda, protrusio acetabuli, global retroversion, isolated cranial over-coverage) have been advocated as a cause of femoro-acetabular impingement (FAI) and early hip osteoarthritis (OA). Different radiographic patterns may advocate the presence of a pincer deformity. The prevalence of these radiographic patterns among general adult population, as their role in early hip OA, is poorly defined.Summary Statement
Background
We evaluated the osteogenic potential of a novel biomimetic bone paste (DBSint®), made of a combination of a human demineralized bone matrix (hDBM) and a nano-structured magnesium-enriched hydroxyapatite (Mg-HA), in a standardized clinical model of high tibial osteotomy for genu varus. A prospective, randomized, controlled study was performed and thirty patients were enrolled and assigned to three groups: DBSint® (Group I), nano-structured Mg-HA (SINTlife®) (Group II) and lyophilized-bone-chips (Group III). Six weeks after surgery, computed tomography-guided biopsies of the grafts were performed. Clinical/radiographic evaluation was performed at six weeks, twelve weeks, six months, one and 2 year after surgery, in order to verify if the graft type influenced the healing rate.Introduction
Methods
Since July 2008 we are experimenting a new cup with iliac screw fixation, developed on the idea of Ring and Mc Minn. Iliac fixation is permitted by a polar screw of large diameter, coated by HA, which allows a compression to bone and a firm primary stability. Moreover it's possible to increase primary stability with further smaller peripherals screws. We present this new cup and report the preliminary results. Since July 2008 to April 2010, 51 cups were implanted. The diagnosis was aseptic loosening in 36 cases, septic loosening treated by two-stage revision in 7, hip congenital dislocation in 5, one case of post-traumatic osteoarthritis, one case of instability due to cup malposition and a case was an outcome of Girdlestone resection arthroplasty. Mean age was of 66 years (31-90).INTRODUCTION
MATERIALS AND METHOD
Replacing a fused or ankylosed hip with a prosthesis has several advantages. It reduces the pain in the lumbar-sacral spine and the ipsilateral knee. It gives a better range of movement and leg length is restored. In this study we present our experience of 50 cases of total hip arthroplasty in fused or ankylosed hips. Aetio-pathogenesis was rhizomelic spondylitis in 35 cases, sequelae of cox it is in 2, posttraumatic in 4, Ankylosis in 6, and fusion in 3. For clinical assessment we used the Merle D’Aubignè score, and for radiographic evaluation we used the Gruen method of area subdivision Of the 50 prosthesis implanted, 3 were removed due to aseptic loosening. The other were the radiographically stable after an average follow-up of 12 years. Preoperative clinical scores were: pain (2.9), range of motion (2.5), and walking (2.1). At the latest exam the scores were: pain (5.5), motion (4.6), walking (4.5). Preoperative leg shortening was 3.5 cm, whereas at the latest exam it was 0.9 cm. Lumbalgia decreased notably in 62%. Total hip arthroplasty may have advantages over fusion on one hand, but on the other it is technically more difficult and gives results that are inferior to common indications. It is therefore important to assess patients (time of fusion, age of patient, residual muscular function) preoperatively to obtain good results.
Preliminary results confirmed that the use of platelet gel and packed medullary cells as adjuvant for the lyophilized bone aid bone repair and graft integration. Morphological and morphometric tests showed that at six week the newly formed bone of group 3 had better mechanical properties. This study shows that the use of platelet gel and packed autologous medullary cells combined with lyophilized bone chips produces a faster and mechanically stronger recovery of bone stock in the treatment of bone defects.
Girdlestone’s arthroplasty is often used to treat septic loosening of hip prostheses. Although this operation provides goodresults with regards to pain and loosening, it causes instability and in the hip and limb shortening that force the patient to use walking aids. From 1990 to 1999 we treated ten cases of revisionhip arthroplasty after Girdlestone’s arthroplasty. Girdleston e’sarthroplasty was carried out in all cases due to sepsis in the previousimplant. Preoperatively all patients underwent granulocyte-labeledscintigraphy. For clinical evaluation we used the Merle D’Aubignè score. From 1990 to 1999 we treated ten cases of revisionhip arthroplasty after Girdlestone’s arthroplasty. Girdleston e’sarthroplasty was carried out in all cases due to sepsis in the previousimplant. Preoperatively all patients underwent granulocyte-labeledscintigraphy. For clinical evaluation we used the Merle D’Aubignè score. Girdlestone’s arthroplasty is very effective for treating septic loosening of hip prostheses, but it causes severe walking impediment. Revision surgery restores limb length and walking. Patients that undergo this treatment should be checked for residual sepsis, which may jeopardize the operation. Currently we are experimenting with spacers with antibiotics and our initial results are promising.
The vast majority of total-joint-replacement components utilized are modular to some degree. Modularity increases the surgeon’s options in both primary and revision THA. Modular prostheses allow the surgeon intra-operative versatility, allowing adjustment of leg length, offset, neck length, and version. This is particularly helpful in CHD, posttraumatic arthritis and in hip revision. Modularity may be applied also to the neck, enlarging the range of choice for difficult cases. Howeverusing of a modular interface increases risk of fretting, wear debris, and dissociation and mismatching of components. A series of 87 revision THA performed between 1997 and 2003 using modular neck was reviewed. The pros-theses are AnCA-Fit with a cementless titanium anatomical stem and Profemur with a tapered revision titanium stem. Both provided with a modular neck inserted by morse taper and a hemispheric press-fitted cup. All the implants have a ceramic-ceramic coupling. Four cases were performed due to recurrent dislocation and 83 for implant loosening. Retrieved necks were studied searching for corrosion. No cases of disassembly or fracture of the neck were observed. Two cases of dislocation were treated with brace. Analysis of retrieved necks confirmed the absence of corrosion. Leg length discrepancy decreased from 57.7% to 22%. One post-operative infection was successfully treated with debridment. Modular neck system allows to correct intraoperatively leg length and offset, choosing between five interchangeable necks available in two lengths: straight, varus-valgus, ante-retroverted. Restoration of hip biomechanics prevents instability. Removal of the neck allows a better surgical exposure when femoral stem is retained. Moreover it allows to maintain ceramic-ceramic coupling. Modular prosthesis has some problems related to risk of corrosion, fretting, fracture or dislocation of components. We observed no cases of disassembly of components or fracture and comparative analysis between retrieved necks and those experimentally studied confirmed absence of corrosion.
The uncemented cup with iliac stem ensures immediate primary stability by fixation to the hipbone in acetabular loosening with severe bone defect. Homologous bone grafts contribute to restoring bone stock, which is a fundamental requirement for long lasting implant stability. From 2002 to 2004 we implanted 23 cups with iliac stems in 22 patients. In 7 cases there was also stem loosening, and so total hip arthroplasty was performed. In 2 patients the defect was grade 2b, in 5 grade 3a, and in 16 grade 3b according to Paprosky. A direct lateral approach was performed in the supine position. Morselized bone grafts were used in all cases by the “impaction grafting” technique, and in 4 cases modelled structural grafts were also employed. Mean follow-up has been 18 months (8–32). So far we have not had any cases of loosening. At follow-up x-rays showed remodelling of the grafts with integration. The cup with iliac stem enables primary stability on healthy bone tissue, and protects the grafts form mechanical stimulation, thus allowing them to integrate and restore bone-stock. It also restores the centre of rotation, and provides functional benefits and implant stability.
From January 2003 to December 2004, 160 consecutive intertrochanteric hip fractures has been treated at the Orthopaedic Rizzoli Institute by a new short intra-medullary rod, which can be distally locked, combined with two sliding screws that insert into the femoral neck and head. The rod is an undersized, titan one. It can be inserted percutaneously. Fractures were classified pre-operatively according to stability and post-operatively according to the type of operative reduction. The failure rate and post-operative stability were then compared according to the type of fracture and to the quality of operative reduction. Results indicate that the pre-operative fracture classification is a significant determinant of post-operative stability. The type of operative reduction was not as significant a determinant of post-operative stability, but an anatomical reduction gives better clinical results. Overall results shows that stable fractures has always healed and only minor complications has been observed. Unstable fractures has a percentage of drawbacks of 1.5% (3 in 160 pts) due to a wrong screw positioning ( 2 proximal and 1 distal ). Three patients died in the early post-operative period due to cardiac failure. No intraoperative fracture, no displacement of the fracture site and no “cut out” were observed.
The groups were thus divided: Group 1: lyophilised bone chips. Group 2: lyophilised bone chips + platelet gel Group 3: lyophilised bone chips + platelet gel + packed autologous medullary cells (Buffy coat). At six weeks X-rays, MRI and needle biopsies were carried out. The tissue underwent morphological and microstructural tests. Results confirmed that the use of platelet gel and packed medullary cells as adjuvant for the lyophilised bone aid bone repair and graft integration. Morphological and morphometric tests showed that at six week the newly formed bone of group 3 had better mechanical properties.
The patients were divided into two groups according to the fracture site. Group 1 included 71 patients with medial fracture, and Group 2 contained 56 patients pertrochanteric or subtrochanteric fracture. All patients were assessed by the Merle d’Aubignè clinical evaluation method. Radiographically, the bone-implant interface was assessed by the presence of radiolucency lines according to the DeLee-Charnley method modified by Martell
The groups were thus divided:
Group 1: lyophilized bone chips. Group 2: lyophilized bone chips + platelet gel Group 3 lyophilized bone chips + platelet gel + packed autologous medullary cells (buffy coat). At six weeks X-rays, MRI and needle biopsies were carried out. The tissue underwent morphological and microstructural tests.