INTRODUCTION

The direct anterior approach (DAA) for total hip arthroplasty has become a popular technique. Proponents of the anterior approach cite advantages such as less muscle damage, lower dislocation risk, faster recovery, and more accurate implant placement for the approach. However, there is a steep, complex learning curve associated with the technique. The present study seeks to define the learning curve based on individual surgical and outcome variables for a high-volume surgeon.

Introduction

Total knee arthroplasty is a highly effective procedure to improve the quality of life in patients with advanced osteoarthritis. The number of these procedures are expected to grow 174% by 2030. This growth rate is expected to economically strain the health care system. A potential solution to alleviate this problem is the utilization of single use instruments (SUI). Potential advantages of SUI include: improved operating room efficiencies, decreased costs associated with traditional instrument management (sterile processing, shipping), and decreased infection risk. The present study examines the clinical results of SUI compared to standard instrumentation. Furthermore, economic modeling is performed to examine the cost savings that is potentially realized with their use.

INTRODUCTION

The Dorr Bone Classification, devised in 1993 is commonly used to categorize bone types prior to hip reconstruction. The purpose of the present study is to quantify the Dorr classification system using 4 morphologic parameters – morphologic cortical index (MCI), canal-flare index (CFI), canal-bone ratio (CBR), and canal-calcar ratio (CCR).

Introduction

Total Knee Arthroplasty (TKA) is highly successful in treatment of end-stage degenerative arthritis of the knee. CT-based Patient-Specific Instrumentation (PSI) utilizes a CT scan of the lower extremity to create a three-dimensional model of the patient's anatomy, plan the surgery, and provide unique patient-specific resection blocks for the surgery.

There are few published studies utilizing CT-PSI. The present study prospectively evaluates clinical, operative, and radiographic outcomes from 100 CT-based TKAs using this technology (MyKnee®, Medacta International S.A., Castel San Pietro, Switzerland).

Between July 2000 and December 2002, 263 consecutive patients across 5 surgical centers underwent to a revision surgery of a failed acetabular component in which TM acetabular components were used.

There were 150 women and 113 men with a mean age of 69.5 years.

The indication for acetabular revision was aseptic loosening in 186 cases (70.7%)

Clinical evaluations were performed using the Harris hip score, the WOMAC and UCLA activity scale.

Implant and screw position, polyethylene wear, radiolucent lines, gaps, and osteolysis were assessed. Preoperatively, acetabular bone deficiency was categorized using the classification of Paprosky et al.

Statistical analysis was performed using nonparametric correlations. Standard life table was constructed, and the survival rate was calculated by means of Kaplan-Meier method.

The overall mean follow-up was 73.6 months (range, 60–84 months), and no patient was lost to follow-up.

The preoperative HHS rating improved from a mean of 43.6 ± 11.4 before revision, to a mean of 82.1 ± 10.7.

None of the patients was re-revised for loosening. The cumulative prosthesis survival was 99.2% at 5 years.

There was no correlation found between the various degrees of acetabular bony defect and the magnitude of clinical results (independent of pre-revision Paprosky grade). The use of component augments allowed us to minimize the volume of morsellized allograft used for defect repair.

TM acetabular component demonstrates promising midterm results similar to those reported by other authors.

Purpose of the study: Despite the help provided for positioning the implants for total knee arthroplasty (TKA), the clinical pertinence of navigation remains a subject of debate. The purpose of this study was to analyse the clinical and radiological outcomes of TKA implanted with and without navigation and to assess the morbidity related to use of the system.

Material and methods: This was a prospective comparative study including 105 patients, mean age 71.5 years divided into two groups: navigated TKA (n=55) and non-navigated TKA (n=50). The same surgeon performed all operations using the same type of implant. We assessed perioperative variables. Clinical and radiological data were analysed pre-operatively then postoperatively with a prospective protocol (2.6 and 12 months) by a single observe. The statistical analysis accepted p< 0.05 as statistically significant.

Results: The two groups were comparable preoperatively regarding age, gender, BMI. Patients in the navigated group had significantly greater persistent flexion (5.32 versus 4.15, p=0.04) and valgus (4.19 versus 3.98, p=0.04) preoperatively. Operative time was measurably but not significantly longer with navigation (90.4 min versus 95.9 min), and was associated with greater blood loss (p=0.02). Intra- and postoperative complications and duration of the hospital stay were similar in the two groups (p> 0.05). The position of the implants was comparable in the two groups (HKA=179±1.58 in the navigation group and 176±3.6 in the non navigation group) with a smaller spread in angle values. At six months, active flexion was significantly better in the non-navigated group (107° versus 101°, p=0.016), but there was no difference in terms of patient satisfaction.

Discussion: Our study was unable to demonstrated any evidence of significant difference between TKA implanted with or without a navigation system. While the navigation system facilitates implant positioning and improves the reproducibility of the operative procedure, the difference is not significant in the hands of an experienced surgeon. Conversely, use of the navigation system, at least during the learning curve, has been associated with longer operative time and greater blood loss. For major deformities however, the navigation technique facilitates reconstruction of the knee joint.

Introduction: Double mobility acetabular implant has a semicircular shape, it is covered with hydroxyapatite, the entire surface has a thickness of 3 mm and its centers of rotation are shifted.

The polyethylene employed is a high density one and it has some chanfers to avoid the cam effect.

Methods and materials: We present the results o an homogeneous series of 200 patients, operated between 2003 and 2007. Clinical and radiographic parameters were analyzed prospectively. The mean follow-up was done during 15 months. Clinical results were evaluated by the HHS at the out patients clinics: previous and post surgery.

Results: From the 200 patients operated (130 women-70 men / Mean age: 81 years old): 57,63% had a primary hip osteoarthritis; 5,77 % femoral necrosis ; 1,13 % rheumatoid arthritis; 16,95 % revision surgeries; 13,45% femoral neck fractures; 3,2% acetabular fractures y 1,5 % hip tumours.

HHS before surgery was 45, 83 points on average (from 12 to 79) y post surgery HHS was 80, 03 points (from 37 to 100), increasing the total score after the arthroplasty in a mean of 34, 17 points

Post surgery complications were as follow: 3 dislocations (1 after an enormous fall and 2 in patients with Alzheimer. In our series there are 50 patients diagnosed of dementia-Alzheimer); 1 per prosthetic fracture (revision surgery); 4 deep infections (2 acute: lavage+ antibiotherapy; 2 late ones: spacer + antibiotherapy +second time surgery); 2 Deep vein thromboses (Eco Doppler +) ; 10 urinary infections; 2 urinary retentions and 17 deaths.

Discussion: Double Mobility acetabular implant has shown good results in all the following indications: Revision surgery, hip osteoarthritis, femoral necrosis, Rheumatoid arthritis, femoral neck and acetabular fractures, hip tumours and as an implant for Computer Assisted Hip Surgery.

Conclusions: The complications founded while this acetabular implant is used appeared with the same percentage than others. The dislocation rate is lower than standard acetabular implants, especially in patients with neuromuscular or cognitive illnesses.

Those clinical results are hopeful and they could increase the number of actual indications (hip osteoarthritis in people over 70 years old, multiple illnesses associated, iterative dislocations…) for the double mobility implant on the future.

Introduction: Reversed prostheses implantation requires screwing of the glenoid component with prefixed angles. This study is to determine anatomical angles of scapula that take part in reversed prostheses implantation.

Material and method: Seventy-three 3-dimensional computed tomography of the scapula and 108 scapular dry specimens were analyzed. Mean age of the CT-3D serie was of 52.59 years old (ranging from 16 to 84). There were 46 females and 27 males. The following measures were made on each patient: length of the neck of the inferior glenoid, angle between the glenoid surface and the upper posterior column of the scapula, angle between the major craneo-caudal glenoid axis and the base of the coracoid process and angle between the major craneo-caudal glenoid axis and the upper posterior column of the scapula. Measures were performed in the AP view as well as in the posterior view of the scapula.

Results: The length of the neck of the anterior glenoid was classified into two groups named ‘short-neck’ and ‘long-neck’ for both three-dimensional computed tomography and cadaveric scapulas with statistically significant differences between both groups (p< 0,001 for the three-dimensional computed tomography scapulas and p=0,034 for the cadaveric group). The angle between the glenoid surface and the upper posterior column of the scapula was also classified into two different types: type I (52° ranging from 48° to 57°) and type II (64° ranging from 60° to 70°) with statistically significant differences between both groups (p< 0,001 for the three-dimensional computed tomography scapulas and p< 0,001 for the cadaveric group). The angle between the major craneo-caudal glenoid axis and the center of the base of the coracoid process averaged 18,25° (ranging 13° from to 27°). The angle between the major craneo-caudal glenoid axis and the upper posterior column of the scapula averaged 8° (ranging 5° from to 18°).

Conclusions:

- scapulas can be classified into two groups regarding the angle between the glenoid surface and the upper posterior column of the scapula with significant differences between them.

INTRODUCTION: Shrinkage is one of the complications observed after allograft meniscal transplantation. Subtle immune rejection and alterations in meniscal permeability leading to nutritional deficit have been suggested as causes of shrinkage. The purpose of this study was to ascertain how freezing, one of the most common procedures used to preserve allografts, alters the collagen’s architecture.

METHODS: 26 fresh human external menisci were harvested in sterile conditions during TKR procedures. 13 of them were immediately frozen to −80° C while the rest were used as controls. All the menisci were cut, processed and preserved in a 2.0% glutaraldehyde and then analyzed with transmission electron microscopy. Four hundred collagen fibrils were recorded and measured in longitudinal and transversal sections in each meniscus. According to the collagen’s periodicity and degree of disruption, loss of banding, degree of collagen packing, fibril size variability and its intrafibrilar oedema, each meniscus was pointed from 0 to 7. Subsequently they were classified in grades ranging from a normal state (grade I; 0 to 2 points) to severe disarray (grade III; 5 to 7 points).

RESULTS: The fibril collagen diameters of those menisci that had been previously frozen showed an average size in the longitudinal section of 14.256 nm, whereas 17.279 nm were seen in the menisci used as controls (p=0.019). In the transverse section, the frozen menisci averaged 13.145 nm and 16.935 nm the controls (p=0.003).

Samples of the 13 previously frozen menisci were classified as grade III in 8 cases (61,54 %), and grade II in 5 cases (38.46 %). They averaged 4.846 points. The control groups were classified as grade I in 6 cases (46.154%) and grade II in 7 cases (53.85 %). The frozen menisci averaged 4.85 points whereas the control group did so 2.46 (p< 0.001)

CONCLUSIONS: The fibril diameters in frozen menisci showed a thinner diameter and had a higher degree of disarray. Therefore, the results suggest that the freezing process alters the menisci’s collagen net. This could partially explain the pathological changes found in shrunken menisci. This is the first work that quantified and qualified methodologically the collagen meniscal architecture and its potential changes.