Aim

The use of piperacillin/tazobactam with vancomycin as empirical antimicrobial therapy (EAT) for prosthetic joint infection (PJI) has been associated with an increased risk of acute kidney injury (AKI), leading to propose cefepim as an alternative since 2017 in our reference center. The present study compared microbiological efficacy and tolerance of these two EAT strategies.

Aim

Current guidelines recommend the combination of vancomycin with either piperacillin-tazobactam (PT) or a third generation cephalosporin (3GC) as empirical antimicrobial therapy of PJI, immediately after surgery. However, clinical and biological safeties of such high dose-combinations are poorly known.

Analysis of the morphology of the distal femur, and by extension of the femoral components in total knee arthroplasty (TKA), has largely been related to the aspect ratio, which represents the width of the femur. Little is known about variations in trapezoidicity (i.e. whether the femur is more rectangular or more trapezoidal). This study aimed to quantify additional morphological characteristics of the distal femur and identify anatomical features associated with higher risks of over- or under-sizing of components in TKA.

We analysed the shape of 114 arthritic knees at the time of primary TKA using the pre- operative CT scans. The aspect ratio and trapezoidicity ratio were quantified, and the post- operative prosthetic overhang was calculated. We compared the morphological characteristics with those of 12 TKA models.

There was significant variation in both the aspect ratio and trapezoidicity ratio between individuals. Femoral trapezoidicity was mostly due to an inward curve of the medial cortex. Overhang was correlated with the aspect ratio (with a greater chance of overhang in narrow femurs), trapezoidicity ratio (with a greater chance in trapezoidal femurs), and the tibio- femoral angle (with a greater chance in valgus knees).

This study shows that rectangular/trapezoidal variability of the distal femur cannot be ignored. Most of the femoral components which were tested appeared to be excessively rectangular when compared with the bony contours of the distal femur. These findings suggest that the design of TKA should be more concerned with matching the trapezoidal/ rectangular shape of the native femur.

Introduction

There is a challenge to detect partial tear of the ACL, the number of bundle injured and the proportion of fibers torn. The MRI was shown efficient to individualize the two anteromedial (AM) and posterolateral (PL) bundles of the ACL. The purpose of this study was to assess the ability of the MRI to detect partial tears of the ACL on axial views to display the AM and PL bundles.

Mobile-bearing total knee arthroplasty was developed to provide low contact stress and reasonably unrestricted joint motion. We studied the results of a cementless, posterior cruciate ligament (PCL)-retaining total knee arthroplasty (TKA), with a mobile-bearing insert in rotation and anterior-posterior (AP) translation (Innex^® Anterior-Posterior Glide, Zimmer).

Kinematic analyses were performed on a series of 51 primary TKA. The patients’ mean age was 71±8 years at operation. Patients were studied at 23 months average follow-up with weight-bearing radiographs at full-extension, 30° flexion and maximum flexion (“lunge” position). Three dimensional position and orientation of the mobile-bearing relative to the femoral and the tibial component during flexion were determined using model-based shapematching techniques.

The average weight-bearing range of implant motion was 110°±14°. In flexion, the mobile-bearing was internally rotated 3°±3° with respect to the femoral component (p< 0.0001) and the tibial tray was internally rotated 5°±7° with respect to the mobile-bearing (p< 0.0001). On average, the mobile-bearing did not translate relative to the tibial base plate from full extension to 45° flexion [0±2 mm (range −5 mm to 6 mm)]. However, the mobilebearing did translate anteriorly 1±2 mm (range −2 mm to 9 mm, p< 0.0001) between 45° flexion and maximal flexion.

We conclude that the mobile-bearing insert showed a progressive increase in internal rotation during flexion. Most of this rotational mobility occurred between the mobile insert and the tibial base plate. With flexion, AP translation did occur between the femoral component and mobile-bearing, and between the mobile-bearing and tibial base plate, but mobile-bearing translation was unpredictable with this unconstrained design.

Purpose of the study: Revision ligamentoplasty can improve function and laxity control but with a less satisfactory result than obtained after primary reconstruction. The purpose of this study was to report management practices and results of revision ACL reconstructions and to assess the course of meniscocartilage damage and determine causes of failures.

Material and method: This was a consecutive series of ten patients, mean age 30 years (range 17–48) who underwent arthroscopic reconstruction. The review was retrospective. Criteria for failure were redevelopment of instability and/or pain, objective laxity, and a KT-100 differential greater than 5 mm. The IKDC protocol was used for the clinical and radiographic assessment. Goniometry, arthroscan and MRI were also performed. The position of the tunnels was analysed according to the Aglietti criteria. The type of surgery, transplant used and status of the menisci and cartilage were analysed.

Results: Mean follow-up of the second revision was 38 months. At last follow-up, seven patients had a global IKDC score of A or B. Two patients had resumed regular sports activities at the same level as before the first tear, four at a lower level. Four had interrupted their sports activities. At the second revision, two patients exhibited medial femorotibial narrowing measured at less than 50%, three had a remodelled medial femorotibial compartment and one a remodelled lateral compartment. All had a partial homolateral meniscectomy and seven had cartilage injuries (3 ICRS III and 1 ICRS IV). At the successive interventions, the number of meniscal lesions, meniscetomies, and cartilage lesions increased (p=0.016, 00098 and 0.0197 respectively). ICRS grade II and IV cartilage lesions were associated with an overall C or D IKCD (p=0.0472). The cartilage lesions were more frequent in knees with meniscal lesions and meniscectomies. The causes of failure of the primary ligamentoplasty and of the first revision (six and seven patients respectively) were poor position of the tunnels (respectively 4 and 1 patients).

Discussion: In 70% of the patients outcome after repeated revision was good or excellent, although the quality declined with increasing number of revisions, in relation to the development of meniscal and cartilaginous lesions. These latter were more frequent and more severe, related to recurrent laxity. Failures were mainly due to recurrent trauma followed by technical errors.

Purpose of the study: Anteversion of the cup during total hip arthroplasty (THA) is crucial for preventing the risk of dislocation. Interest has recently focused on an anatomic element often observed in the operative field during hip surgery: the transverse acetabular ligament (TAL). The TAL has become a landmark both for conventional procedures (Beverland) and for computed-assisted surgery. The purpose of this original research was to study the anteversion of the TAL in relation to the anterior pelvic plane in order to determine whether it could be a valid landmark for positioning the cup using the Lewinnek criteria (35±20° anteversion according to the Murray definition).

Material and methods: Eight laboratory cadavers (three male, five female, mean age 82±3.3 years) were dissected; the pelvis was removed. Fifteen fresh healthy hips (free of trauma or degenerative disease) were also used for the study. The orientation of the peri-acetabular structures was measured with the probe of the BrainLab^® navigation system and the Motion Analysis^® system (Santa Rosa. CA) at the laboratory of biomechanics and biomechanical shocks (INRETS, Bron). The Lewinnek reference plane (anterior pelvic plane) was defined from the anterosuperior iliac spines and the pubic tubercles.

Results: The anatomic version of the TAL varied from −8 to +13.3 (mean 1.9); the anatomic version of the horns of the semilunate surface from −12.2 to +14 (mean 3); for the labrum the figures were +17.4 to +41.8 (mean 26.63). Anteversion of the TAL and the horns were well correlated (r=0.8) significantly (p=0.001).

Discussion: There is no other study concerning the anatomic orientation of the TAL, the horns and the labrum. Archbold was the first to consider the TAL (1000 cases, posterolateral access, 28 mm head) as a reliable constant landmark for positioning the cup (0.6% dislocation). In our study, the anatomic version of the TAL was found outside the safety zone of Lewinnek. This is a supplementary argument for questioning the reliability of the Lewinnek criteria based solely on nine cases of dislocation and criticised by several authors (non-specific for each patient).

Conclusion: Anteversion of the labrum is situated within this safety zone. The TAL does not position the cup in the Lewinnek safety zone, which remains controversial.

Introduction: Autologous chondrocyte implantation was introduced in 1994 by Brittberg and Peterson for the treatment of large full-thickness focal chondral defects. The purpose of the present study was to evaluate the mid-term results of this technique in a group of patients with post-traumatic chondral defects of the knee.

Materials and Methods: Fifteen patients underwent autologous chondrocyte implantation between 2001 and 2006 and were prospectively assessed preoperatively, at 3, 6, 9, 12 months, 3.5 years and last follow-up with use of standard rating scales (IKDC subjective score, pain Visual Analogic Scale (VAS), Brittberg and Peterson’s score). The inclusion’s criteria were: pain VAS more than 40/100, age between 18 and 50 years, focal chondral defect in weight bearing area grade 3 or 4 and informed and signed consent. Patients with varus or valgus deformities with malalignement more than 5 degrees, knee instabilities and signs of arthritis on radiographs were excluded. The same experienced surgeon performed all the procedures.

Results: Fourteen patients were reviewed at the latest follow-up. The mean age of the patients at the time of autologous chondrocyte transplantation was 37.7 years (range, 30 to 45). The mean duration of symptoms was 2.9 years (0.5 to 7). Nine patients (83%) had previous operations on the index knee. The defect was located on the medial femoral condyle in 11 patients and on the lateral femoral condyle in 3. The mean lesion size was 1.80 cm² (range, 1.5 to 3.5 cm²) after débridement. After a mean duration of follow-up of 6 years (3.3–7.8), 84% of the patients had improvement on a patient self-assessment questionnaire. The IKDC subjective score and Brittberg-Peterson’s score were all improved. The mean IKDC subjective score increased from 40 (27.6–65.5) preoperatively to 60.2 (35.6–89.6) at the latest evaluation. The mean pain VAS decreased from 66.3 (44–89) to 23.2 (0–77). The Brittberg and Peterson’s score decreased from 54.4 (11.8–98.2) to 32.9 (0–83.9). Two patients (16.7%) felt no improvement by the chondrocyte transplantation at the last follow-up. Two complications occurred: graft periosteum hypertrophy treated by débridement and a pulmonary embolus.

Discussion: Our results are similar than those reported in the literature. These outcomes are encouraging and need further follow-up to confirm the long-term efficacy of autologous chondrocyte implantation.

The purpose of this study was to compare 2 different strategies of management for ACL rupture in skeletally immature patient.

In group 1, patients were treated in a children hospital by ACL reconstruction with open physis. In group 2, patients were treated in an adult hospital by delayed reconstruction at skeletal maturity assessed radiologically.

Fifty six consecutive patients were included in this retrospective study. Mean time from injury to surgery in group 1 and 2, was 13.5 and 30 months, respectively.

In the overall series, a long time from injury to surgery increased the number of medial meniscal tear (p< 0.0001), but had no influence in the number of lateral meniscal tear (p=0.696). Patients in group 2 exhibited a higher rate of medial meniscal tears (41%) compared to group 1 (16%) (p=0.01). Both groups had the same rate of lateral meniscal tears (p=1). Despite there was no difference between the 2 studied groups in type and location of menisci lesion, patients in group 2 underwent more partial menisectomy (63%) than patients in group 1 (16%) (p=0,014).

One temporary tibial valgus deformity was reported and spontaneously resolved. No definitive growth disturbance was noticed. At 27 months mean follow-up, patients in group 1 expressed better subjective IKDC than in group 2. Objective IKDC and radiological results were similar in both groups.

Early ACL reconstruction in skeletally immature patient, especially if the patient is more than one year to be skeletally mature, has to be promoted despite of growth disturbance risk. This strategy will decrease medial meniscus lesions and partial meniscectomies which occurred more frequently when ACL reconstruction had been delayed until skeletal maturity.

Introduction: The anterior cruciate ligament (ACL) can be anatomically divided into two bundles: the anteromedial (AM) and the posterolateral (PL). These two bundles have unique contributions to load transfer across the knee joint.

Material and Methods: We retrospectively reviewed the clinical results of a consecutive series of 25 patients who underwent partial ACL reconstruction. In 22 cases AM bundle reconstruction was performed, and in 3 patients isolated PL bundle reconstruction was performed.

The 25 patients included 7 women and 18 men with an average age of 29.2 years at the time of surgery.

Preoperative evaluation was conducted using manual Lachman test, pivot-shift tests, KT-1000, magnetic resonance imaging and passive stress radiographs of both knees. In all cases preoperative clinical evaluation was graded C as per the IKDC scoring system. The preoperative side-to-side anterior laxity measured by means of the KT-1000 was 5.8 mm in case of AM bundle rupture and 4.3 mm in case of PL bundle rupture.

All the patients underwent single-bundle reconstruction of the ACL under arthroscopic assistance (one single incision technique).

In case of AM bundle repair, the type of graft used was all autologous and included bone-patellar tendon-bone in 14 cases, 4-strand hamstring tendons in 5 cases and 2-strand hamstring tendons in 3 cases.

In case of PL bundle repair, 2-strand hamstring tendons transplant was used in the 3 cases.

Results: In all cases, postoperative clinical evaluation was graded A as per the IKDC knee examination scoring system. No abnormal sagittal laxity was found with the Lachman manual test. Postoperative IKDC knee subjective evaluation score averaged 81.3 % [58–95] at an average of 9 months follow-up.

Postoperative side-to-side anterior laxity measured with KT-1000 averaged 0.46 mm in case of AM bundle rupture and 0.5 mm in case of PL bundle rupture.

Postoperatively, all the patients had full extension of the knee. The flexion was the same as contra lateral knee in 92 % of the cases. We had no postoperative complication.

Discussion: Diagnosis of partial ACL rupture is often difficult. If the AM bundle is torn, the Lachman manual test is soft and the pivot-shift test is more often equal or glide. If the Lachman manual test is intermediary between firm and soft and the pivot-shift test is clunk, PL rupture has probably occurred.

The size of the graft was smaller than in one bundle procedures and was matched with the size of the bundle reconstucted. Peroperative technical difficulties were to preserve the healthy bundle and to drill the femoral tunnel in case of posterolateral bundle reconstruction.

Conclusion: This study showed consistent postoperative results. If partial rupture of the ACL can be diagnosed, isolated AM or PL bundle reconstruction should be considered.

Purpose of the study: The double-mobility concept was introduced for clinical applications for total hip arthroplasty in 1976. The concept preserves joint range of motion while increasing stability. In this study we evaluated the consequences of these advantages in terms of polyethylene wear, measuring wear both on the concave and convex surfaces and volumetrically.

Material and methods: Forty polyethylene inserts were explanted and analyzed. Explantation had been performed for mechanical or septic failure after eight years implantation on average. Mean age of patients at implantation was 46 years. After examining the gross aspect of the insert, surface analysis was performed with direct measurement of changes in the curvature using a BHN 706 position sensor for the inner concave surface and lateral projection for the outer convex surface. Estimated measurement error was ±5μm for each method; the manufacturer's tolerance for production of the inserts was 50μm. Volumetric wear was determined by reference to the manufacturer’s data. Student’s t test for paired series was applied.

Results: At gross inspection, all inserts had lost the strips originally present on the convex surface; 40% presented visible wear of the retaining ring. Mean annual wear (± standard deviation, SD) obtained with the measuring system was 9±9 μm/yr) for the convex surface and 73 ± 69 μm/yr for the concave surface. Total annual wear, the sum of inner and outer surface wear, was 82±72 μm/yr. The mean volumetric wear was 28±28 mm3/year for the convex surface and 25±23 mm3/year for the concave surface and 53.4±40 mm3/year for total wear.

Discussion: Total wear for these 40 double-mobility inserts which had functioned in vivo was not greater than the values reported for the metal-polyethylene bearing with 22.2 mm femoral heads. The double mobility is not associated with greater wear. While there was no significant difference between the wear volume of the convex versus the concave surfaces, the differentials wear were widespread, which can be considered to result from functional differences.

Purpose of the study: The reversed total shoulder prosthesis is one of the treatments currently proposed for excentered glenoid osteoarthritic degeneration with massive rotator cuff tears. In light of the mediocre or at best highly variable results obtained with osteosynthesis or humeral arthroplasty for four-fragment fractures of the proximal humerus, indications for the reversed total shoulder prosthesis have been widened to include this category of traumatology patients. The purpose of this prospective study was to report outcome with the reversed prosthesis used for complex fracture of the proximal humerus in subjects aged over 70 years.

Material and methods: Ten patients, mean age 76 years, underwent surgery performed by the same surgeon to insert a Delta (DePuy) reversed prosthesis for four-fragment complex displaced fracture of the proximal humerus. The deltopectoral approach was used for all patients. The rotator cuff status was assessed intraoperatively. Clinical (Constant score) and radiological assessment were noted at 24 months.

Results: During the operation, only three of the ten shoulders presented a full thickness rotator cuff tear. One patients developed a complication requiring revision: early dislocation revised with a retaining polyethylene insert without recurrent dislocation. There were no cases of glenoid loosening at last follow-up. The weighted Constant score was 65/100. A pain-free shoulder was achieved in all ten patients. Anterior elevation was 130° on average, internal rotation reached hand to buttocks and active external rotation 20°.

Discussion: In patients aged over 70 years presenting a complex four-fragment fracture of the proximal humerus, the reversed prosthesis enables improved function and restoration of satisfactory joint movement. Early postoperative recovery and the gain in pain relief are encouraging factors. There was however unsatisfactory restoration of active rotation. For the elderly subject, free of a massive rotator cuff tear, rapid recovery after insertion of an reversed prosthesis should be balanced against the possible preservation of active rotations with an anatomic prosthesis.

Purpose of the study: Double mobility prostheses are increasingly popular. Evidence in the literature demonstrates greater efficacy for the treatment and prevention of prosthesis instability. Ten-year survival is to the order of 95% (Aubriot, Philippot). One of the drawbacks is the risk of prosthetic head displacement outside the retaining polyethylene ring, i.e. intraprosthetic dislocation. We searched for factors causing this complication.

Material and methods: We reviewed retrospectively 67 files concerning intraprosthetic dislocation among a series of Novae cups (Serf) implanted from 1982. Head diameter was 22.2 mm for 59 cases, with a Pro stem (Serf) for 31 cases and a PF stem (Serf) for 36. Each type of stem has a specific neck design. All patients underwent revision surgery; the retaining function of the explanted pieces was analyzed.

Results: Mean time to the complication was 91 months; mean patient age at implantation was 54 years. Early cases exhibited macroscopically intact retaining capacity. Intermediary and late cases exhibited macroscopic wear with an oval shaped retaining ring. For three cases, intraprosthetic dislocation followed an episode of dislocation reduced under sedation. The cups measured 53 mm on average. The rate of calcification was high in this population (15 cases of Brooker grade 3 or 4). Mean survival was significantly different between the Pro and PF stems.

Discussion: Early dislocations were related to insufficient retaining capacity of the initially inserted ring. After a corrective measure by the manufacturer, this type of early complication has disappeared. Late dislocations resulted from impingement wear. Dislocation of a prosthesis with a double-mobility cup increases the risk of intraprosthetic dislocation after reduction; reduction procedures should thus be performed under general anesthesia with curare treatment. We analyzed the different parameters involved: head-neck relation, activity, periprosthetic calcification, cup diameter, resurfacing of the prosthetic neck. Observations were compared with data in the literature.

Purpose of the study: The iliopsoas bursa lies immediately anteriorly to the hip joint capsule and in certain cases there exists a natural communication between a hip prosthesis and the iliopsoas bursa, enabling formation of an inguinal mass by distension of the bursa.

Material and methods: We report six cases of a pseudo-tumoral mass which developed in the femoral scarpa triangle revealing a complication of total hip arthroplasty. These six patients, aged 66–79 years had their prosthesis for 11.5 years on average (range 4–20 years). Three had a history of acetabular dysplasia. All complained of pain. Five patients presented a palpable mass in the inguinal region. Two patients underwent emergency surgery, one for suspected strangulation of a crural herniation and the second for septic inguinal adenopathy. In two patients the clinical presentation was related to the local effect of the mass: lower limb edema with recurrent phlebitis due to venous and lymphatic compression, and femoralgia due to compression of the femoral nerve. The underlying prosthetic complications were: aseptic loosening (n=4), polyethylene wear (n=2), infection (n=1). All patients underwent revision surgery to change the prosthesis. The cystic formation was drained without resection. Symptoms resolved after replacement surgery in all patients.

Discussion: Palpation of an inguinal mass with signs of local compression in a patient with a painful total hip arthroplasty is a sign of a prosthetic complication (infection, loosening, wear). The diagnostic work-up should include bacteriology and plain x-rays of the hip joint. Bone scintigraphy may be contributive. Arthrography can demonstrate presence of a communication. Computed tomography provides the best visualization of the mass and its relations with neighboring organs. A duplex-Doppler is needed in all cases to search for thromboembolic complications prior to surgery. We chose not to resect the cystic formation in our patients, preferring treatment of the intra-articular cause. The fact that the mass and local its effects resolved in all cases with no recurrence at last follow-up leads us to recommend this attitude for typical presentations.

Introduction: Infection after hip or knee replacement occurs with low frequency but shares high morbidity. Aim of this study was an evaluation of incidence and risk factors related to post operative infection after joint lower limb joint replacement in an orthopaedics unit.

Material and methods: This is a monocentric, retrospective, case control study over the years 2000 to 2002. All first intention Total Hip and Knee Replacement and revision cases for mechanical reasons that became infected were identified. Demographic, surgical and medical variables, potentially associated to prosthetic infection were compared for these patients to a control group of non ifected patients over the same time, matched for sex, age and surgery type.

Results: Ten patients, all male, contracted post operative joint infection, out of 630 Total Hip or Knee Arthroplasties. This represented 1.2% after hip replacement and 3.1% after knee replacement. Bacteriological datas showed a majority of Staphylococal infection (5 aureus, 1 epidermidis), 2 among these being resistant to meticillin, but also evidence of ENT commensals (2 Streptococci milleri, 1 Actinomyces) and one epidermal commensal (Propionobacterium acnes). Univariate analysis: datas associated with increased risk of infection were diabetes melitus (OR 9.3; CI 95% 1.4–63), operating time exceeding 120 minutes (OR15.5 ; CI 95% 1,73–139,66), superficial wound infection (odds ratio 29; CI95% 2,77–303,32), coinfection outside the operation site (urinary tract , dental infection) (OR: 9,3 ; CI 95% 1,33–63,2). In our study an MNIS score higher than 1, autologous transfusion, locore-gional anaesthesia with or without the use of a catheter, antibioprophylaxis that did not comply with national recommendations could not be drawn as a risk factor.

Discussion: Incidence of infection and risk factors related to infection in our study were found similar tothe results of published datas. The small number of events (10 cases) did not allow us to realize multivariate analysis and could explain that some known risk factors such as non recommended antibioprophylaxis, could not be elicitated. However these results suggested the need to reevaluate the system of prevention of infection in our centre such as protocolization of antibioprophylaxis and screening for and treatement of perioperative coinfection.

Purpose: Acetabular revision has become a challenging situation due to the importance of bone stock loss encountered in SOFCOT stage III acetabula. The number of failures due to loosening are explained by the strong mechanical stress on the bone grafts or inadequate restitution of the rotation centre of the hip. The purpose of this study was to evaluate mid-term results of the Kerboull support used to achieve anatomic recentring of the hip and progressive weight bearing on the bone grafts.

Material and methods: This retrospective series included 54 acetabular revisions performed for stage III loosening between 1989 and 1996. A Kerboull support was used in all cases. The patients were assessed with the Postel Merle d’Aubigné score and radiographically on plain pelvis films in order to search for recurrent loosening or arthroplasty failure. The log rank test was used to compare actuarial survival.

Results: The series included 62% women. Mean age was 62.3 years (33–87). This was the first revision for 78% and a second or more revision for 22%. The preoperative Postel Merle d’Aubligné score was 9.18 points. This score was 12.3 postoperatively, 15.6 at one year, 15.5 at five years and 14.8 at last follow-up. Dislocation was the most frequent complication, with 55% occurring on cups more than 46° oblique. Grafts were considered radiographically integrated in 58% of the cases. There were 5.5% failures due to migration, 13.8% due to fracture of the superior screw. The actuarial survival was 97.4% at three years, 94.7% at four years, 89.2% at five years and 73% at seven and ten years.

Conclusion: On the basis of these good short-, mid- and long-term clinical and radiographic results, we recommend Kerboull support for the treatment of stage III acetabular loosening.

Purpose: Polyethylene wear in total hip arthroplasty remains the most limiting factor for implant survival. Several predictive factors are well identified, but the position of the articulating pieces remains to be studied in detail. We searched for a correlation between polyethylene wear and the position of the femoral and acetabular pieces, particularly the femoral offset.

Material and methods: Sixty-six patients underwent total hip arthroplasty for osteoarthritis or osteonecrosis. The patients were reviewed at 10.8 years (four bilateral prostheses). The preoperative, immediate postoperative (1 month) and last follow-up (10 years) AP pelvis views were digitalized. A dedicated software traced the different axes for measurement. Wear at ten years, femoral offset, cup eccentration or medialisation, ascent or descent, and cup inclination were measured.

Results: Mean polyethylene wear was 1.23 mm at ten years with linear curve of 0.11 mm/yr. Preoperative femoral offset was restored in 71.4% of the cases. Univariate regression analysis revealed that only femoral offset was correlated with less wear at ten years. Polyethylene wear at ten years fell from 1.26 mm for preoperative offset restitution less than 98% to 1.13 mm for restitution greater than 102%.

Discussion: Image processing allowed greater accuracy in the measurement of polyethylene wear. The rate of wear reported in the literature ranges from 0.1 to .015 mm/yr. Restitution of femoral offset guarantees less wear due to the reduction in the resultant force applied on the articulation as well as stress on the implants. Furthermore hip stability is improved. Several factors are involved in production of wear debris and correct restitution of the centre of rotation is only one of the elements which reduce wear.

Conclusion: Wear was not excessive in this series. Among the position parameters, only femoral offset had an influence, having a beneficial effect on polyethylene wear. This emphasises the importance of having a wide variety of implants available in order to respond to the different anatomic presentations of the femur.

Purpose: Amstuz introduced the notion of a lever arm ratio to describe the relationship between the abductors and weight in arthroplasty. He demonstrated that patients may limp if defective lateralisation produces a low lever arm ratio. We analysed a continuous series of arthroplasty patients with excellent outcome at one year to compare restoration of lateralisation with the preoperative status. We also performed the same analysis in a series of patients who limped after arthroplasty, excluding cases with classical causes of failure. We then compared these two series.

Material and methods: We had a series of 100 arthroplasties with excellent results at one year. These patients had undergone unilateral arthroplasty and had a healthy contralateral hip. The centre of the arthroplasty head was identified on preoperative and one-year AP x-rays of the pelvis (same magnification). We measured the lateralisation in relation to the femoral axis. The position of the cup was measured with a U ratio. Results were expressed in percent restitution of the preoperative status. Amstutz’s lever arm ratio was also measured. Finally, we measured the distance between the pubic symphysis and the outermost point of the femur on the prosthetic and healthy side.

We also had a second population of twelve patients presenting persistent limping at one year with no objective cause. The same parameters were measured for this population.

Results: We found that we had achieved only partial restitution of the initial lateralisation and had a tendency to medialise the acetabulum. The restitution of lateralisation was significantly different between the series with excellent outcome and the series with limping.

Discussion: Deficient lateralisation appears to be a factor involved in persistent limping. There is a threshold for restitution of lateralisation; limping is always observed under this threshold. Data in the literature reveal a very wide variability in lateralisation. It would thus appear important to restore the initial lateralisation to avoid limping; this has led us, like others, to use lateralised implants for certain patients.

Purpose: We report a prospective series of 70 explantations of the femoral pivot via a transfemoral approach required due to septic and aseptic loosening.

Material and methods: Aseptic loosening was observed in 61 cases, septic loosening in 9. The extended posterolateral approach was used to remove the implant in all cases and a femoral segment (Wagner method). Reconstruction of the femur was achieved with locked stems without cement (65 patients) or a long stem without cement (1 patient). Reimplantation was not attempted in four patients. Bone grafts were not used. Mean follow-up in this series was 3.5 years. The PMA score was used for clinical assessment. Radiographic assessment of segment healing and bone regrowth around the implant was done by measuring the cortical index.

Results: We observed a significant gain in the PMA score of more than 9 points. We had one intraoperative fracture of the femoral segment and two episodes of early dislocation. All femoral segments healed. Osteogenesis failed in three cases with fracture of the locking screw. There were also two cases of late fracture of the trochanter. At one year, bone regrowth measured from the cortical index was greater than 10% on the average.

Discussion: We discuss the characteristic features of this type of surgery in comparison with other solutions for femoral revision: operative time, blood loss, choice of implants, later weight bearing. We also found that this technique allows easier implant removal and more effective cleaning of the femoral shaft in the event of septic surgery with fewer cases of intraoperative accidents (malposition, femoral fractures). We were able to demonstrate that this method of femur reconstruction without bone graft provides a stimulation of osteogenesis in the floating segment. Stem locking provides primary stability in 100% of the cases. Secondary stability was achieved in 90% due to the quality of the newly formed bone.

Purpose: A new locked nail is proposed for the treatment of proximal fractures of the humerus. This simple system with self-locking screws was designed for all types of proximal fractures. The purpose of this prospective study was to determine indications and identify limitations.

Material and methods: We used the proposed fixation method sparing the cuff muscles and using a cup-and-ball technique for complex three or four-fragment fractures with major displacement. All nails were locked proximally, with at least two screws, and distally. Early joint mobilisation recommended for this type of osteo-synthesis was applied diversely. This series included 50 fractures of the upper humerus which were all treated with a Telegraph nail between January 2000 and January 2002. We identified 18 fractures of the surgical neck and 32 cephalotuberosity fractures. Mean age was 67 years, range 23–94 years.

Results: The Constant score at maximum follow-up of 24 months was used to assess clinical outcome. Bone healing was effective in all cases but there were several complications: secondary displacement (n=3), fracture of proximal screws (n=5), nail ascension (n=3), rupture of the long head of the biceps (n=1), and stiffness at flexion (n=12), which required removal of the implant in five patients and prosthetic replacement in one.

Discussion: The self-locking screws used with this nail provide excellent stability. Despite the rigid assembly, we observed displacements which led to screw failure and tilting heads. The distal locking screw appears to play a deleterious role in impaction of the fracture. The high rate of complications, 26% in this series, has led to reconsider using plate fixation for complex fractures in young patients and ascending pinning with the Apprill or Hackethal method to avoid aggression on the rotator cuff for fractures of the surgical neck. The Telegraph nail thus does not appear to be indicated only for complex fractures of osteoporotic bone; arthroplasty should be retained for this indication.