Purpose: The purpose of this study was to assess outcome after first-intention total hip arthroplasty for fresh fractures of the acetabulum in elderly patients. Material and methods: We present a retrospective analysis of 18 recent fractures of the acetabulum observed in nine men and nine women, mean age 74.8 years which were treated by first-intention total hip arthroplasty. The fractures were considered equivalent to acetabular bone deficits observed at revision of total arthroplasty (five grade III, 13 grade IV in the SOFCT 1988 classification). The prosthesis was implanted 15.6 days (mean) after initial trauma and included a metal-backed acetabular implant (except one case) and a bone autograft (except three cases). Complete weight bearing was authorised on day 3 postop for five patients, and at six weeks for ten; at three months for the other three. Mean follow-up was 2.5 years. Thirteen surviving patients were reviewed clinically and radiographically. Five patients who had died were also included in the analysis using data reported by family before death. The Postel-Merle d’Aubigné (PMA) and Harris scores were recorded. Survival curves were plotted. Radiological assessment included bone healing, status of the prosthetic assembly, presence of a lucent line or signs of loosening in the three acetabular zones described by De Lee and Charnley. Results: The mean functional scores were 13.6/18 (PMA) and 71.8/100 (Harris). There were no cases of infection or dislocation. Median Kaplan-Meier survival was six years. The one-year survival rate was 94.4%. Five deaths were recorded, all due to causes independent of the surgical intervention. Radiologically, all fractures had healed. There were no mechanical complications and no signs of acetabular loosening. Discussion: Several authors have demonstrated that prognosis is poor in elderly subjects undergoing surgical osteosynthesis or functional treatment due to the presence of risk factors (osteoporosis, comminution, deferred surgery due to poor general status). Prolonged bed rest may also have life-threatening consequences. Other work has emphasised the very high rate of complications after revision surgery for dismounted material, post-traumatic deterioration, or osteonecrosis. The absence of early deaths and the low rate of intervention-related morbidity in this series of elderly patients is in agreement with a very small number of publications devoted to this topic. Conclusion: This therapeutic attitude enables early verticalisation avoiding the complications related to the bedridden state in the elderly. In addition, subsequent revision for osteonecrosis of the femoral head or post-traumatic deterioration can be avoided. These results have incited us to pursue this therapeutic option

Fracture of the acetabulum can lead to degenerative arthritis of the hip, avascular necrosis of the femoral head, or both. Total hip arthroplasty is a common form of surgical treatment when significant joint changes and pain are present. Ten patients with fracture acetabulum were treated in this study using metal on metal total hip arthoplasty. The initial fracture was posterior wall fracture in one patient, posterior column fracture in one patient, transverse fracture in 2 patients, fracture dislocation in 3 patients and fracture posterior wall and column in 3 patients. The indications of arthroplasty were secondry osteoarthritis after internal fixation or after conservative management or collapse of the femoral head. Arthroplasty was done after an average period of 1.8 years (range from 1 to 4 years). After a follow up period ranged from 3 to 7 years with a mean of 4.6 years, the Harris hip score was improved from a mean of 51 (range 20 to 65) to a mean of 92.5 (range 90 to 95). Infection occurred in one case and two stages revision was done. Another case developed loosening of the acetabular component and was revised using cementless cup fixed with screws and bone graft. Metal on metal THR after acetabular fracture are relatively uncomplicated and lead to a good outcome despite the difficulties faced during the procedure

Aims

Posterior column plating through the single anterior approach reduces the morbidity in acetabular fractures that require stabilization of both the columns. The aim of this study is to assess the effectiveness of posterior column plating through the anterior intrapelvic approach (AIP) in the management of acetabular fractures.

Acetabulum fractures caused by civilian firearms represent a unique challenge for orthopaedic surgeons. Treatment strategies should include the assessment of infection risk due to frequently associated abdominal injuries and maintenance of joint function. Still, internationally accepted treatment algorithms are not available. The aim of the study was to increase knowledge about civilian gunshot fractures of the acetabulum by describing their characteristics and management at a high-volume tertiary hospital. All adult patients admitted to our hospital between January 2009 and December 2022 with civilian gunshot fractures of the acetabulum were included in this descriptive retrospective study. In total our institution treated 301 patients with civilian gunshot fractures of the hip joint and pelvis during the observation period, of which 54 involved the acetabulum. Most patients were young males (88,9%) with a mean age of 29 years. Thirty patients (55,6%) had associated intraabdominal or urological injuries. Fracture patterns were mostly stable fractures with minor joint destruction amenable to conservative fracture treatment (n=48, 88,9%). Orthopaedic surgical interventions were performed in 21 patients (38,9%) with removal of bullets in contact with the hip joint via arthrotomy or surgical hip dislocation as most frequent procedures. Most patients received antibiotics on admission (n=49, 90,7%). Fracture related infections of the acetabulum were noted in six patients (11,1%) while the mortality in the study population was low with one demised patient (1,9%) due to the trauma burden. Most civilian acetabulum gunshot fractures are associated with intraabdominal or urological injuries. In comparison to the literature on extremity gunshot fractures, there is an increased risk of infection in our study population. The decision for surgical wash-out and bullet removal should be based on contamination and anticipated joint destruction, while osteosynthesis or primary arthroplasty are rarely necessary for these injuries

Fracture risks are the most common argument against the use of Ceramic on ceramic (CoC) hip implants. Question: is ceramic material at risk in case of severe local trauma?. Over a long period, we tried to identify patients with a CoC prosthesis (Ceraver Osteal°)who did sustain a trauma. This was conducted in three different institutions. Eleven patients were found: 9 males and 2 females aged 17 to 70 years at time of index surgery. Accident occurred 6 months to 15 years after index: one car accident, five motorcycle accident, five significant trauma after a fall, including one ski board accident. Consequences of these trauma were: six fractures of the acetabulum with socket loosening in 4 that needed revision, two femoral shaft fracture, one orifed and one stem exchanged, one traumatic hip dislocation associated to loosening of the socket revised at 10 years, and one traumatic loosening of the socket. Ten had no consequence on ceramic integrity. One experienced a fracture of the patella from a dashboard trauma, a liner shipping was discovered during socket revision 2 years later. This is the only case of possible relation between trauma and ceramic fracture. In a more recent longitudinal study on 1856 CoC prosthesis performed from 2010 to 2021, 29 severe traumas were identified with no consequence on Ceramic material. From this limited case study, it can be assumed that Pure Alumina Ceramic well designed and manufactured, will not break after a significant trauma

Purpose: Appropriate treatment of fractures of the acetabulum is well known but there is a risk of subsequent degeneration. Few reports of series reviewed after ten years are available. We report a series of 136 treated fractures of the acetabulum with a mean follow-up of 16 years. Material and methods: Between 1972 and 1996, a total of 554 fractures of the acetabulum were treated. An independent operator reviewed 136 cases. The Judet Letournel classification was applied. Reduction was studied on the AP and 3/4 oblique views of the pelvis using the SOFCOT (November 1981) criteria. Intra- and postoperative parameters (blood loss, complications) were noted. Functional outcome was assessed with the Postel-Merle-d’Aubigné score. Results: Orthopaedic treatment was used for 38% of the fractures. Forty-one percent were non-displaced and 54% were minimally displaced; 5% of patients had a contraindication for surgery. Reduction was achieved in 28% of the displaced fractures. Among the patients treated orthopaedically, 71% had a good or very good outcome. Anatomic reduction was achieved in 80%. The main complications were sciatic nerve injury (14%), heterotopic ossifications (18%), infection (5%) and intraarticular screws (5%). Good or very good outcome was achieved in 69%. A total hip arthroplasty was implanted in 19% at mean 8 years. Factors significantly related with poor outcome (p< 0.05) were age, posterior displacement, and surgeon experience. There was a good correlation between the function score and radiological signs of osteoarthritis. Discussion: This is the longest follow-up reported in the literature. For operated patients, the percentage of good and very good outcomes was lower than in other series despite a good rate of anatomic reduction which thus is not a guarantee of good long-term outcome. Other prognostic factors found in the literature include fracture of the femoral head, type of fracture, and quality of the reduction. Long term follow-up remains essential for pertinent analysis of joint surgery

Purpose: The surgical approach is an essential element for precise reduction and rigid fixation of fractures of the acetabulum. In cases where the anterior column is mainly involved and total hip arthroplasty (THA) is indicated, classical approaches do not allow double assess to the anterior column necessary for reduction and fixation and to the femoral canal for insertion of the prosthesis. Combining Heuter’s anterior approach and Letournel’s ilio-femoral approach provides access to the anterior column and to the often associated posterior hemi-transverse fracture, while allowing insertion of the total hip prosthesis. Material and method: This combined approach was used for ten among 60 THA performed for fracture of the acetabulum. Seven were primary procedures and three were differed reconstruction procedures. Mean patient age was 60.6 years (range 50 – 85 years). Fracture types were: acetabular wall and anterior column (n=8), anterior column and posterior hemi-transverse (n=2). All fresh fractures exhibited major acetabular damage associated with fracture of the femoral neck. A hybrid THA was used for all cases after fixation of the fracture. The femoral heads were used as graft material for deficient anterior columns in two patients and as “piecemeal” grafts for the others. Results: Mean follow-up was 36 months (range 24–35 months). At last follow-up all fractures had healed and all acetabular components exhibited solid fixation with no sign of migration. The mean outer diameter of the ace-tabular components inserted was 56 mm (52–64) using a 2 mm press-fit and one screw. The only complication was one postoperative anterior dislocation. Pain relief and function were satisfactory in all patients at last follow-up with a Postel Merle d’Aubigné score of 16 (13–18). Discussion: This anterior surgical approach enables good access to the acetabular walls and anterior columns, allowing solid fixation and relatively easy THA. The Kocher-Langenbech approach is still better in case of posterior deficiency or when posterior fixation requires space for inserting an acetabular component. We reserve it for THA used to treat fresh fractures of the acetabulum with major damage to the acetabulum and/or the femoral head, with or without neck fracture in patients aged 55 years or more. For differed reconstruction, we also use this approach if the acetabular damage involves the anterior column

Aims. Accurate placement of acetabular and femoral stem components in total hip arthroplasty (THA) is an important factor in the success of the procedure. A variety of free hand or navigated techniques is reported. Survivorship and complications have been shown to be directly related to implant position during THA. The aim of this cadaver study was to assess the accuracy of the placement of the components in THA using patient specific instruments (PSI) in combination with a 3D planning software and the direct anterior approach. Method. Patient specific instruments (PSI) were developed to guide the surgeon during THA that were 3D printed with their bone models following a 3D software planning protocol (LPH software V2.5.1, Onefit-Medical, Eos Imaging Company, Besancon, France). Acetabular guides: cup, offset and straight reamer handle and impactor, femoral- and chisel guides were used in each THA (Fig. 1). To define anatomic bone landmarks and to generate a 3D model of each hip joint CT scans were performed preoperatively. The planning of component position was done by one surgeon (AZ) preop. Surgery was performed by two experienced surgeons (AZ, SD) on cadaver specimen with 4 hips in two separate series. A total of 8 hip replacements were evaluated pre- and postoperatively using CT-scans of each hip joint to compare planned to achieved results. Mechanical simulations of the guides were carried out to verify that there were no conflicts between the different instruments. To meet the ISO standard 16061: 2015 the compatibility of the instruments with the guides has been checked. Parameters were evaluated in 3D pelvic and femoral planes: center cup position, inclination angle, anteversion angle, cutting height and plan orientation, anteversion angle, flexion/extension angle, varus/valgus angle, anatomical and functional leg length, offset. Acceptance criteria: postop. parameters evaluated must not have a deviation of more than 5 degrees, 2,5 mm according to preop. planning. For every THA the test protocol has been completely realized. Results. The difference between the preop. and postop. measures in the first series of 4 hips revealed 2 outliers because of fractures of the acetabulum in 2 cases, related to bad cadaver quality. In the second series we found satisfactory results comparing the planned preop and postop component position (Fig. 2). For example difference of leg length showed a mean absolute of 1,58 mm, standard deviation 1,21 mm (min 0,62; max 3,34 mm). Offset revealed a mean absolute of 1,62 mm, standard deviation 0,57 mm (min 1,06; max 2,14 mm) concerning the difference between preop. planning and result postop. Conclusion. Accurate and safe placement of total hip components in THA, both acetabular cup and stem, performing the direct anterior approach can be achieved using a 3D preoperative planning along with patient specific instruments. The results of the cadaver study tests are promising and that is to be proven in the clinical setting and by application in the future

Aims

The aims of this study were to evaluate the incidence of reoperation (all cause and specifically for periprosthetic femoral fracture (PFF)) and mortality, and associated risk factors, following a hemiarthroplasty incorporating a cemented collarless polished taper slip stem (PTS) for management of an intracapsular hip fracture.

Purpose: The purpose of this retrospective study was to evaluate at minimal 5 years follow-up outcome in a consecutive series of total hip arthroplasties implanted for fracture of the acetabulum. Material and methods: The series included 53 arthroplasties implanted between January 1980 and December 1995 in 53 patients, 16 women and 37 men, mean age 53.1 years (24–84). The initial fracture involved the acetabular wall in 18 patients, one column in seven and two columns in six. It was a complex fracture in eleven cases and classification was unknown in the eleven other hips. Orthopaedic treatment was used for 23 patients and surgery for 30. Mean time between fracture and arthroplasty was 16.4±10.8 years. Cemented Charnley-Kerboull implants with a metal-polyethylene bearing were used. The Postel-Merle-d’Aubigné (PMA) score was used to assess functional outcome. The actuarial survival was determined. Results: At five years minimum follow-up, 33 patients were alive and had not undergone revision at mean follow-up of 12.4±3.8 years (7–21). Six patients had had revision of the acetabular and/or femoral element, five patients had died, and seven were lost to follow-up. Revisions were required for cup wear associated with periacetabular osteolysis. The mean preoperative functional score was 10.6±2.5 versus 16.2±2.8 (8–18) at last follow-up (Wilcoxon rank test, p< 0.0001). Cumulative survival, taking revision as failure, was 90.3±6.5% at 15 years (95%CI 77.6–100%) for hips treated orthopaedically versus 66.5±14.5 (95%CI 38.1–94.9%) for hips treated surgically. The difference for the analyzable hips was not significant (logrank, p=0.69). Discussion: The results of this series confirm that the long-term risk of mechanical failure of total hip arthroplasty for fracture of the acetabulum is high

Aims

Pelvic discontinuity is a rare but increasingly common complication of total hip arthroplasty (THA). This single-centre study evaluated the performance of custom-made triflange acetabular components in acetabular reconstruction with pelvic discontinuity by determining: 1) revision and overall implant survival rates; 2) discontinuity healing rate; and 3) Harris Hip Score (HHS).

Objective. To investigate the relationship between the pattern of pelvic or acetabular fracture, and bladder injuries. Methods. A total of 173 patients admitted at our Academic Hospital from January 2006 to March 2012 with cystograms done for pelvic or acetabular fractures were studied retrospectively. Records of pelvic X-Rays, CT scans and cystograms were reviewed. Tile's classification and Young & Burgess classification were used for pelvic fractures and Judet & Letournel classification system for acetabular fractures. Results. Out of 173 patients 16% had bladder injuries of which 22% were intra-peritoneal and 70% were extra-peritoneal. The bladder injuries mostly occurred among male patients; 16 males compared to 9 female patients. Out of the 21 fractures of the acetabulum only 2 sustained bladder injury and they were secondary to gunshot wounds. Lateral compression fractures accounted for 67% of bladder injuries. Motor vehicle accidents were the leading mechanism of injury accounting for 117 patients in total and 81% of those with bladder injuries. Among the patients with bladder rupture 55% had at least 3 rami involved and only one patient (4%) with 1 ramus involved had a bladder injury. Overall 44 (34%) of patients with 3 or more rami fractured had bladder injury. Conclusion. Bladder injury appears to be related to the mechanism of injury. We recommend that a cystogram be done routinely when a patient presents with a type III lateral compression fracture. In isolated acetabulum fractures, single ramus fractures and lateral compression type I fractures, request for cystogram should be correlated with clinical signs and symptoms, and not done routinely. NO DISCLOSURES

Introduction. The clinical and functional outcome following simultaneous fractures of the acetabulum and pelvic ring represent a challenge for the clinician and are currently obscure in the existing literature. Patients and Methods. Between January 2003 and July 2009 all patients with combined pelvic and acetabular fractures were included in this prospectively study. Demographic details, mechanism of injury, ISS, surgical procedures, post-operative course, length of hospital stay, and radiological (Matta's score) and functional outcomes (The Merle d' Aubigne hip score) were recorded. The minimum follow up was 12 months (12–72). Results. Out of 520 cases, 30 (21 males) patients met the inclusion criteria. The mean age was 32. 55% sustained lateral compression, 40% combined mechanism and 5% anterior/posterior type of injury pattern. 15 out of the 30 patients had sustained other injuries. The mean time from injury to definite reconstruction was 7 days (3–14). Ilioinguinal approach was used in 20 patients, Pfannestiel in 2 and Kocher-Langebeck in 4. A wheelchair was used initially in 22 cases. The median time to FWB was 3 months. One patient underwent a THR at 18 months. 19 patients scored the full 18 points of the Merle score. Matta radiological score was excellent in 16 patients, Good 11, Fair 2, Poor 1. Conclusion. The management of these injuries poses many difficulties to the trauma surgeon. With the available expertise in place good outcomes can be obtained as seen in this series of patients

Fracture of the acetabulum can result in damage to the articular surface that ranges from minimal to catastrophic. Hip arthroplasty may be required for more severe injuries due to marked articular surface damage, post traumatic degenerative changes, persistent malunion or nonunion, or occasionally avascular necrosis and destruction of the femoral head. These problems may be seen following both closed and open fracture treatment, but prior open reduction and internal fixation often makes subsequent THA more difficult due to soft tissue scarring and retained hardware. In select acute acetabular fracture cases with severe initial comminution of the joint, open reduction and fixation can be technically impossible or so clearly destined to early failure that initial fracture treatment with combined limited fixation and simultaneous THA is the best option, especially in osteoporotic elderly fracture patients. Problems which may be encountered during any THA in a patient with a prior acetabular fracture include: difficult exposure due to soft tissue defects and scarring, presence of heterotopic ossification, and nerve palsy from the original fracture or subsequent osteosynthesis. Retained hardware can present significant challenges and frequently is left in place or removed in part or completely, when intraarticular in location or blocking preparation of the acetabular cavity and placement of the cup. Additional potential problems include residual deformity and malunion, persistent pelvic dissociation or nonunion of fracture fragments, cavitary or segmental bone loss from displaced or resorbed bone fragments, and occasionally occult deep infection. Preoperative assessment and planning should include careful consideration of the most appropriate surgical approach, which may be impacted by the need for hardware removal. Screening laboratory studies and aspiration of the hip may prove helpful in excluding associated deep infection. Intraoperative sciatic nerve monitoring may be of assistance in patients with partial residual nerve deficits or where extensive posterior exposure and mobilization of the sciatic nerve is needed for hardware removal or excision of heterotopic ossification. Metal cutting tools to allow partial removal of long plates and adjunctive equipment for removal of broken or stripped screws should be routinely available during these cases. Careful preoperative planning regarding implant and reconstructive options can also ensure availability of proper components and equipment. Often implants and techniques developed for revision surgery for management of major bone deficiencies are needed. Reported results suggest that surgery is frequently prolonged, can be associated with greater blood loss and may result in increased risk of post-arthroplasty heterotopic ossification when compared to routine primary procedures. Bone stock and fracture union may be better in patients with prior internal fixation than in those with nonoperative treatment of major displaced acetabular fractures. Available long-term results document more durable results with lower rates of aseptic loosening with uncemented acetabular fixation compared to cemented acetabular components. These patients are at higher risk of revision and failure than patients undergoing THA for simple osteoarthritis, though initial short-term results are comparable to conventional hip arthroplasty patients, as long as early wound healing problems and deep infection can be avoided, which is a greater risk for acute THA for initial fracture care. The application of newer implant designs, highly porous ingrowth materials, and methods for management of acetabular bone deficiency developed for revision THA have helped improve results in this challenging subset of primary THA patients

Factors influencing the results of revised cemented sockets with bone grafting have been studied in 249 cases. Freeze-dried allografts in 77 and fresh frozen in 172 cases have been used. The average follow-up was 8 years 11 months for the freeze-dried group and 2 years 11 months for the fresh frozen cases. There were 13 postoperative dislocations, 20 TNU, 4 thromboembolic complications, 4 delayed wound healing and 2 intraoperative fractures of the acetabulum. There have been 11 re-revisions: 8 for aseptic loosening, 2 for dislocation and 1 for infection. Radiographic evidence of loosening was seen in another 38 cases. The acetabular bone stock at the time of revision and initial stability of socket fixation had a significant influence on the outcome. Direction of socket migration before surgery appeared to predict risk of failure. The primary pathology, type of bone graft and grafting technique also had an effect

Purpose of study. To review the treatment and outcomes of paediatric pelvic ring injuries in the UK. Methods and results. We performed a retrospective review of all pelvic fracture admissions to an English paediatric major trauma centre (MTC) from 2012 to 2016. A total of 29 patients were admitted with pelvic ring injuries with a mean age of 11 years (4- 16yrs). Road traffic accident was the mechanism in majority (72%), followed by fall from height (24%). Femoral shaft fracture was present in 5 (17%), head injury in 5 (17%), chest injuries in 5 (17%) and bladder injury in one child. 48% patients needed surgical procedures for fractures or associated injuries. We differentiated injuries according to the classification system of Torode and Zeig. 17% were Type A, 3% Type B, 48% Type C and 31% Type D. Almost all (93%) patients were treated conservatively. 51% of patients were allowed to mobilize full weight bearing after a period of bed rest. Non-weight bearing mobilization was recommended for fractures extending into the acetabulum, sacral fractures, unstable fracture patterns or associated fractures (neck of femur, femoral shaft and tibial shaft). Surgical fixation occurred in two patients. Both of these patients had significantly displaced Type D fractures. Only 44% of patients were back to sports at six months. Conclusions. Pelvic ring injuries are rare within the paediatric population and are associated with a high incidence of concomitant injury and significant functional morbidity. Their treatment should involve a multidisciplinary approach, which includes specialist in the care of pelvic trauma

Purpose of the study: Correct implant position is one of the factors of long-term success of total hip arthroplasty (THA). Acetabular architectural defects caused by trauma can create difficult situations leading to potential complications and poor outcome. The purpose of this study was to examine retrospectively the results of THA implanted after fracture of the acetabulum treated surgically. The objective was to analyse the specific features and search for factors favouring poor outcome. Material and method: The series included 43 patients who had a THA implanted after treatment of an acetabular fracture. Mean age at trauma was 44.5 years (range 16–87). Five patients had a THA immediately, mean age 75 years (63–87). Thirty eight patients had osteosynthesis. According to the Letournel classification, the fracture was elementary in 12 cases and complex in 26. In ten patients, there was residual joint incongruence measuring more than 2 mm after osteosynthesis. The hips evolved to degenerated joint (n=34) and or necrosis (n=10). Results: Mean time from acetabular osteosynthesis to THA was 94.6 months (range 3–444), excluding those patients whose THA was implanted at the time of the osteosynthesis. Arthroplasty required removal of the osteosynthesis material (n=11), insertion of a supportive ring (n=14) associated with a bone graft (n=13). The acetabular implant was considered to be well positioned according to the Pierchon criteria in 16 hips and was lateralised (n=21) and/or ascended (n=17) in the other hips. Inclination was 42.8 on average, range 10–18. The five-year survival was 80%. Discussion: Arthroplasty after surgical treatment of an acetabular fracture is a difficult procedure. Complementary procedures are often necessary complicating the surgery and increasing the risk of perioperative complications, particularly infection. It is difficult to position the acetabular implant, increasing the risk of postoperative instability and early loosening. This study demonstrated the difficulties of implanting a THA in this context where the revision rate is significantly higher than in first-intention THA

Correct component positioning in hip resurfacing is a key determinant for a successful outcome. The aim of the study was to compare the radiographic and perioperative clinical parameters between navigated and non-navigated resurfacing groups and to look at the effect of navigation on the learning curve. Pre and post operative radiographs were analyzed with respect to neck-shaft angle, implant-shaft angle, notching, lateral position, and cup inclination. The target implant position was to place the femoral component in relative valgus to the neck-shaft angle using the smallest component without notching the femoral neck. The target cup position was 40–45 degrees inclination. Statistical analysis was performed comparing the two groups with respect to implant position, complications and differences between experienced verses inexperienced surgeons. Data was recorded for 51 patients (24 navigated, 27 conventional). There was no significant difference in implant-shaft angle or presence of notching between the two groups. There were two cases of notching in the non-navigated cohort. Lateral positioning (central placement stem, centering component on shaft) was significantly more accurate for the navigated cases (P< 0. 001). There was no significant difference in cup inclination between the two groups. In the non-navigated group three patients were converted to a total hip replacement (one fracture, one impingement pain, one intra-operative notching) and there was 1 case of medial wall fracture of the acetabulum. There was a 14.8% complication rate for the non-navigated group with no complications in the navigated group. Complications experienced 2.6% vs. training 17.4%. Training navigated 0% vs Training non-navigated 30%; Experienced nav 0% vs. experienced non-navigated 5.5%. Positioning of the femoral component in the lateral plane and A-P head-neck ratios is significantly more accurate with the use of computer navigation. Navigation allows for a relative valgus implant-shaft angle that is as accurate as conventional jigs. Navigation is useful as a teaching tool with a reduction in the learning curve and better radiographic placement of components

Aims: The purpose of this study was to quantify the amount of cell viability and cartilaginous damage present in non-reparable human osteoarticular fragments removed at the time of acetabular fracture surgery. Material and Methods: The cases of 6 patients with comminuted fractures of the acetabulum were prospectively analyzed. Average age was 39 years, and none of them had evidence of preexisting hip pathology. Loose small osteoarticular fragments that were not reparable were microscopically analyzed to assess in-situ cell viability. Observations were divided into (i) depth of chondrocyte death from the articular surface, and (ii) structural matrix damage and cell death under regular histology. The depth of cell death was classiþed as mild between 1 and 15%, moderate from 15 to 30%, severe from 31 to 60% and total from 61 to 100%. Results: Five of the patients were classiþed as having only mild amount of chondrocyte death and one specimen had a moderate amount of chondrocyte death. The articular surface damage was mainly located on the superþcial zone of the cartilage. Discussion and conclusion: Most of the chondrocytes on small osteochondral fragments removed from displaced intraarticular acetabular fractures were still viable after having received a substantial amount of trauma

Aim of the study. Aim of this study was to find out which factors influence the outcome after both column fractures of the acetabulum. Methods. We performed a retrospective analyse of 115 patients with both column acetabular fractures. The period between the injury and follow-up ranges between 2 and 19 years, 5,7 years on average. The initial displacement, the presence of a dislocation of the hip and fractures of the femoral head were analyzed on the initial radiographs. Postoperative displacement was classified according the classification of Matta. The common classifications of Helfet (posttraumatic arthrosis), Ficat/Arlet (femur head necrosis) and Brooker (periarticular calcification) were used to radiologically classify the long term results. Statistics were performed by the Chi-square-test. Results. We could find a clear tendency between the result of replacement and the radiological long-term result. 10 % of the patients with a postoperative displacement 1 mm had a joint failure compared to 28 % of the patients with 2–3 mm and 31,6 % with >3 mm displacement. In cases with good radiological results the average of initial displacement was 11,4mm but it was 17,8 mm for patients with a bad result. This difference is high significant (p=0,008). If the primary displacement was < 10 mm the rate of joint failure was 10,85%, whereas the rate increased up to 27,5% in patients with primary displacement > 10mm. Patients with hip dislocations had no significant higher risk for a joint failure (21,5% without vs. 25,9% with dislocation). Also patients with injuries of the femoral head had no significant (p>0,05) worse outcome. 19,8% of the patients without femoral head injury suffers on joint failure in comparison to 15,4% (2) of the patients with impression or contusion of the femoral head. The presence of intraarticular fragments is accompanied by a worse result (p=0,041). In 50% of the cases with intraarticular fragments a joint failure appeared whereas only 18% of the patients without fragments developed joint failure. Discussion. Matta could show in 1996 that anatomic replacement is a very important factor for a good outcome after acetabular fractures. These findings were supported by other publications. Our data show that there is a significant worse outcome after nonanatomical replacement. Several authors could show the presence of additional factors which predict the outcome independently of the replacement. In our data the primary displacement and the presence of intraarticular fragments showed a high influence. Dislocation of the hip, injuries of the femoral head and the presence of acetabular comminution had no significant influence but their number was maybe too small to detect it. Conclusion. Anatomical replacement is the major goal to avoid joint failure in the treatment of both-column acetabular fractures. Additional factors including the primary displacement and intraarticular fragments have a worse influence independent of the replacement