Prognostic factors for all-inside meniscal repair. A 87-case series.

INTRODUCTION: Repair is indicated for tears in non-degenerative menisci. The literature reports a 15% failure rate for all-inside repair. The aim of the present study was to determine prognostic factors for failure of all-inside meniscal repair. The study hypothesis was that epidemiological, clinical and surgical factors affect success. MATERIAL AND METHODS: A retrospective study included 87 meniscal repair procedures, with or without anterior cruciate ligament (ACL) tear. Lesions were located in red-red or red-white zones. After freshening, repair comprised an all-inside arthroscopic technique using the FasT-Fix® system (Smith & Nephew), with (70.1%) or without ligament reconstruction; all ACL tears were reconstructed. Preoperative data comprised: age, gender, smoking status, sports activity, trauma-to-surgery time, body mass index (BMI), frontal morphotype, and IKDC score. Intra- and postoperative data comprised: meniscal lesion characteristics, location, number of sutures, type of ACL reconstruction, presence of chondropathy, authorized postoperative ranges of motion, and IKDC score. Failure was defined by secondary meniscectomy. RESULTS: At 31 months' follow-up, there were 13 failures (15%). Mean postoperative IKDC score was 88.19 (range: 64.37-98.95). Bucket-handle lesion (P=0.006) and BMI>25 (P=0.014) emerged as significant factors of poor prognosis. DISCUSSION: The present failure rate matched those reported in the literature. The more extensive the lesion, the higher the risk of failure. High BMI incurs mechanical stresses that increase the risk of failure. LEVEL OF EVIDENCE: IV, retrospective cohort study.

Medial patellofemoral ligament reconstruction for patellar instability following total knee arthroplasty: A review of 6 cases.

INTRODUCTION: Patellar instability is a frequent cause of total knee arthroplasty (TKA) failure. In cases of post-arthroplasty patellar instability, the medial structures may be damaged. The objective of this study was to study the effectiveness of medial patellofemoral ligament (MPFL) reconstruction. We hypothesized that MPFL reconstruction will effectively realign the patella, making it a viable treatment option for managing post-arthroplasty patellar instability. MATERIAL AND METHODS: In this retrospective study of six patients treated by four different surgeons, patients were included if they had a recurring or permanent patellar dislocation after undergoing TKA. Patients were excluded if the patellar instability was painful but did not result in dislocation. Each patient underwent MPFL reconstruction using the gracilis; additional procedures could be performed depending on the diagnosis. One patient required TKA revision because of an abnormally rotated femoral implant. The main outcome measure was the non-recurrence of the dislocation. The IKDC and Kujala functional scores, joint range of motion and patellar tilt on X-rays were analyzed preoperatively and at the last follow-up. RESULTS: At a mean follow-up of 23 months (6-46), none of the patients experienced a recurrence of the patellar dislocation. Only one patient had no improvements in the functional outcome scores. The patellar tilt was reduced in all patients. CONCLUSION: MPFL reconstruction-in isolation or with femoral component revision-is effective at treating post-arthroplasty patellar instability. It has its place in the treatment of patellar dislocation following TKA and its indications must be based on exact analysis of the reasons for the instability. LEVEL OF EVIDENCE: IV - Retrospective cohort study.

Ground-reactive forces after hallux valgus surgery: comparison of Scarf osteotomy and arthrodesis of the first metatarsophalangeal joint.

AIMS: The purpose of this study was to analyse the biomechanics of walking, through the ground reaction forces (GRF) measured, after first metatarsal osteotomy or metatarsophalangeal joint (MTP) arthrodesis. PATIENTS AND METHODS: A total of 19 patients underwent a Scarf osteotomy (50.3 years, standard deviation (sd) 12.3) and 18 underwent an arthrodesis (56.2 years, sd 6.5). Clinical and radiographical data as well as the American Orthopaedic Foot and Ankle Society (AOFAS) scores were determined. GRF were measured using an instrumented treadmill. A two-way model of analysis of variance (ANOVA) was used to determine the effects of surgery on biomechanical parameters of walking, particularly propulsion. RESULTS: Epidemiological, radiographical and clinical data were comparable in the two groups and better restoration of propulsive function was found after osteotomy as shown by ANOVA (two way: surgery × foot) with a surgery effect on vertical forces (p < 0.01) and a foot effect on anteroposterior impulse (p = 0.01). CONCLUSION: Patients who underwent Scarf osteotomy had a gait pattern similar to that of their non-operated foot, whereas those who underwent arthrodesis of the first (metatarsophalangeal) MTP joint did not totally recover the propulsive forces of the forefoot. TAKE HOME MESSAGE: The main findings of this study were that after surgical correction for hallux valgus, patients who underwent scarf osteotomy had a gait pattern similar to that of their non-operated foot in terms of forefoot propulsive forces (Fz3, Iy2), whereas those who underwent arthrodesis of the first MTP joint had not. Cite this article: Bone Joint J 2016;98-B:641-6.

Recovery of gait pattern after medial patellofemoral ligament reconstruction for objective patellar instability.

Gait pattern alterations were previously reported in association with objective patellar instability (OPI). Gait pattern comparison between a series of patients having undergone medial patellofemoral ligament (MPFL) reconstruction and a sample of control subjects. Thirty patients at 6 months postoperatively after MPFL reconstruction and thirty control subjects were enrolled in the study for a clinical and biomechanical assessment including gait analysis at three selected walking rates using the GAITRite(®) system. The mean raw IKDC score was 73 (± 19), and the mean Kujala knee function was 84 (± 17.5). The study of gait did not demonstrate any significant difference between the two groups at a normal and fast walking rate. At a 10 km/h running speed, the single-support phase was significantly shortened by a mean 2.33% (p < 0.05), the swing phase by a mean 2.64% (p < 0.05) and the double-support phase by a mean 3.49% (p < 0.05) on the operated side. MPFL reconstruction reported good midterm functional and clinical results in the management of OPI. At 6 months postoperatively, the patient gait pattern was similar to that observed in healthy subjects at a normal and fast walking speed. However, our study revealed persistent gait abnormalities at a 10 km/h running speed. These gait alterations seemed to be related to the ligament reconstruction in itself due to the higher strain applied on the reconstructed MPFL during running cycle (10 km/h). Level of evidence IV.

Results of anatomic gracilis MPFL reconstruction with precise tensioning.

BACKGROUND: The medial patellofemoral ligament (MPFL) is the most commonly injured structure in patients with objective patellar instability. The objective of this study was to prospectively evaluate the clinical and radiographic results of MPFL reconstruction in 50 patients with chronic patellar instability. METHODS: Fifty patients with chronic patellar instability, aged 15-39 years, were included. The MPFL was reconstructed using a free gracilis autograft tendon. Two anchors were used for patellar fixation, and femoral fixation was achieved with an interference screw placed into a tunnel between the adductor tubercle and medial epicondyle. The graft was tensioned to 10 N with the knee in 30° flexion. IKDC and Kujala scores were assessed pre- and post-operatively. Patellar tilt was measured from CT scans with the quadriceps relaxed and contracted, both pre- and post-operatively. RESULTS: The follow-up period was 7 to 44 months (mean: 25 months, SD 10.3). The mean raw IKDC score increased from 51.5 preoperatively to 71.7 at last follow-up, the mean overall IKDC score increased from 38.5 to 61.7 and the Kujala score increased from 48.3 to 82.4. On CT scans, the mean patellar tilt went from 24° to 16.2° with the quadriceps relaxed and 27.7° to 18.1° in contraction. No recurrent dislocation was observed. CONCLUSION: This technique of MPFL reconstruction provided significant improvements in IKDC and Kujala scores and significant reduction in patellar tilt. No recurrent dislocations were observed during the study period.

Medial patellofemoral ligament reconstruction: clinical and radiographic results in a series of 90 cases.

INTRODUCTION: Among the numerous techniques available, medial patellofemoral ligament (MPFL) reconstruction is increasingly used for the surgical treatment of objective patellar instability. The main objective of the present study was to assess efficacy in preventing recurrence of patellar dislocation and in correcting radiographic patellar tilt. The study hypothesis was that MPFL reconstruction, isolated or with associated bone surgery, by restoring "favorable" graft anisometry, provides a good trade-off between patellar stability and absence of postoperative stiffness. MATERIALS AND METHODS: Eighty-seven patients (90 reconstructions) presenting with objective patellar instability were prospectively included. The standardized procedure comprised MPFL reconstruction using the gracilis tendon. Femoral fixation used an interference screw in a blind tunnel between the adductor magnus tubercle and the medial epicondyle; patellar fixation used 2 anchors. Complementary distal bone graft was associated in 21 patients due to a preoperative tibial tubercle-trochlear groove (TT-TG) distance exceeding 20mm or to patella alta. Functional IKDC and Kujala scores and radiographic measurement of patellar tilt and femoral tunnel position were assessed preoperatively and at end of follow-up. RESULTS: Mean follow-up was 24.3months (range, 6-49months). Three patients showed recurrence of patellar dislocation. Mean Kujala score rose from 53.88 preoperatively to 86.24 postoperatively, and mean real IKDC score from 45.15 to 73.92 (P<0.001). Patellar tilt decreased significantly between pre- and postoperative X-ray (P<0.001). DISCUSSION: MPFL gracilis reconstruction provides good clinical results and good radiologic correction of patellar tilt, making it a technique of choice in the treatment of objective patellar instability. LEVEL OF EVIDENCE: Level IV. Retrospective case series study.

Assessment of joint position sense deficit, muscular impairment and postural disorder following hemi-Castaing ankle ligamentoplasty.

INTRODUCTION: Hemi-Castaing ligamentoplasty is a treatment for chronic ankle instability, accused of weakening a powerful stabilizing muscle: the peroneus brevis. OBJECTIVES: To assess proprioceptive and muscular impairment following hemi-Castaing and impact on postural control. METHODOLOGY: A retrospective series of 21 patients underwent clinical (Karlsson, AOFAS) and proprioceptive assessment with isokinetic assessment (evertors and invertors) on a Con-Trex dynamometer and postural assessment on a Win-Posturo force platform, at a minimum 6 months postsurgery. RESULTS: At a mean 18 months' follow-up, mean Karlsson score was 84 and AOFAS score 88. Ankle joint position sense error was less on the operated than on the healthy side. Evertor strength deficit with respect to the healthy side was 4.7% (ns) at 30°/s and 5.7% (ns) at 120°/s in concentric mode and 6.6% (ns) in excentric mode. After surgery, the evertor/invertor ratio was >1 (in favor of the evertors). Postural values were significantly higher for the operated ankle. DISCUSSION-CONCLUSION: Hemi-Castaing ligamentoplasty provided excellent clinical and functional results. It did not disturb the agonist/antagonist balance of the ankle muscles, and harvesting a half peroneus brevis did not impair evertor isokinetic force. Joint position sense was not impaired; indeed, deficits with respect to the contralateral side showed improvement. LEVEL OF EVIDENCE: Retrospective study.

Multiscale analysis of anterior cruciate ruptures: Prospective study of 49 cases.

INTRODUCTION: Partial anterior cruciate ligament (ACL) ruptures are common. The ability to distinguish between various types of ACL ruptures preoperatively would allow surgeons to choose the most appropriate surgical treatment. HYPOTHESIS: A partial ACL rupture can be diagnosed preoperatively. MATERIAL AND METHODS: The goal of this single-center, prospective study was to establish correlations between various macroscopic types of ACL ruptures determined by arthroscopy with data from clinical examination, knee laxity measurements (GnRB(®)) and magnetic resonance imaging (MRI). The 49 patients included over a six-month period had a diagnosis of ACL rupture based on the clinical examination. Four arthroscopy categories were defined based on the French Arthroscopy Society (SFA) classification. Each patient had their knee laxity measured, a preoperative MRI performed and a clinical exam done in the operating room before the procedure. RESULTS: During arthroscopy, the ACL was described as "Complete tear" in 23 of 49 patients, "Healed onto PCL" in 12, "Posterolateral bundle preserved" in 14 and "Healed into notch" in none of the patients. The clinical exam alone could not discriminate between the various types of ruptures (P>0.05). With MRI, the sensitivity was 84% and the specificity was 92% for partial ACL rupture. There was a strong correlation between MRI and the various arthroscopy groups (P<0.05). There was a significant difference (P<0.05) between partial and complete ruptures in terms of knee laxity. CONCLUSION: This study helped define the relationships between arthroscopy findings, MRI findings and knee laxity measurements. It is feasible to make a preoperative diagnosis of partial ACL rupture. LEVEL OF EVIDENCE: Level IV, prospective cohort study.

Dual mobility retentive acetabular liners and wear: surface analysis of 40 retrieved polyethylene implants.

PURPOSE OF THE STUDY: Dual mobility systems with retentive acetabular liners have been used in clinical practice for total hip arthroplasty since 1976. The dual mobility system preserves a wide range of motion while providing greater stability. This study measured wear on the concave and convex surfaces of 40 retrieved polyethylene liners, to evaluate the advantages of this system in relation to wear. MATERIAL AND METHODS: Forty polyethylene inserts that had been removed due to infection or mechanical failure after a mean 8 years were analyzed. The mean age of patients at arthroplasty was 46 years old. Macroscopic analysis was followed by surface analysis with direct measurement of changes in the curvature radii. The internal concave surface was measured in three dimensions using a 4-mm stylus (BNH 706). External convexity was measured by lateral projection. The estimated error was ± 5 µm for both measurement methods. Manufacturers' tolerance for these implants was approximately 50 µm. Linear wear and wear volume was determined by comparing the measured dimensions with the theoretical dimensions of new liners. RESULTS: Macroscopically, all of the pieces studied had lost the initial machined grooves on the convex surface; 40% of the pieces showed visible wear of the retentive collar. Mean annual convex surface wear was 9 µm (SD 9µm) and 73 µm (SD 69 µm) for the concave surface. Mean total wear, which was the sum of the wear on the convex and concave surfaces was 82 µm (SD 72 µm). Wear volume was 28.9 mm(3)/yr for the convex surface (SD 27.6) and 25.5 for the concave surface (SD 23.2) with a mean annual total wear volume of 54.3 mm(3)/yr (SD 39.6). DISCUSSION: Total wear in the 40 dual mobility liners that had functioned in vivo was similar to that reported in metal-polyethylene bearings with 22.2mm femoral heads. The results of wear in both the convex and concave surfaces show that wear with the dual mobility system was not increased compared to conventional metal-polyethylene bearings, while providing better retention and greater stability. CONCLUSION: The use of dual mobility acetabular liners is an attractive solution when a metal-polyethylene bearing is needed. The increased joint stability is not associated with increased wear.

Recovery of rotators strength after Latarjet surgery.

The purposes of this study were to prospectively determine changes in rotator cuff strength before and after surgical shoulder stabilization by Bristow-Latarjet procedure and to better estimate time needed for rotator cuff strength recovery. 20 patients with recurrent anterior posttraumatic shoulder dislocation underwent internal (IR) and external (ER) rotator isokinetic evaluation before and 3, 6 and 21 months after Bristow-Latarjet surgery. In a seated position with 45° of shoulder abduction in the scapular plane, both shoulders were evaluated concentrically with a Con-Trex® isokinetic dynamometer at 180°âˆ™s (- 1), 120°âˆ™s (- 1) and 60°âˆ™s (- 1). 3 months post-surgery, IR and ER strength of the operated shoulder were significantly lower than before surgery (- 28 ± 20% for IR, - 17 ± 17% for ER) (P<0.05). At 6 and 21 months post-surgery, IR and ER strength were comparable to strength before surgery; strength recovery is seen at 6 months post-surgery with long-term maintenance at 21 months. Given the weakness 3 months post-surgery, return to sports (including overhead and contact sports) should be discussed, and 6 months post-surgery may be a better point for an athlete to resume practicing sports. Isokinetic rotator cuff strength evaluation appears to be relevant in helping to determine the need of continuing strength rehabilitation. Pre-surgical evaluation contributes to the relevance of later comparisons.

The role of the medial ligamentous structures on patellar tracking during knee flexion.

PURPOSE: The influence of the medial patellar ligamentous structures on patellar tracking has rarely been studied. Thus the main purpose of this cadaveric biomechanical study was to determine the influence of the medial patellofemoral (MPFL), medial patellomeniscal (MPML) and medial patellotibial (MPTL) ligaments on the three-dimensional patellar tracking during knee flexion. This study was conducted using a validated cadaveric optoelectronic protocol for analysis of patellar kinematics. METHODS: For each cadaveric knee study, four successive acquisitions were performed; first was studied patellar tracking in healthy knees, then the junction between MPFL and vastus medialis obliquus (VMO) was sectioned, the MPFL was released at its patellar attachment and finally was released the insertion of the MPML and MPTL. RESULTS: In this study, the MPFL accounts for 50-60% of the medial stabilization forces of the lateral patellar shift during patellar engagement in the femoral trochlea. This work confirm and clarify the role of the MPFL as the primary stabilizer of the patella during the initial 30° of knee flexion. Moreover, this study shows no significant results regarding the stabilizing action of the VMO on the patella during knee flexion. CONCLUSION: This in vitro study, conducted with an experimental protocol previously validated in the literature, helps quantify the actions of the MPFL, the VMO, and the MPML/MPTL respectively, and identify areas of joint motion where these structures have the most significant influence. This confirms the importance of reconstruction in the treatment of chronic patellar instability. During its reconstruction, care should be taken to adjust the MPFL balance during the initial 20°-30° of flexion.

Revision total hip arthroplasty using a reconstruction cage device and a cemented dual mobility cup.

INTRODUCTION: The main causes of total hip arthroplasty (THA) revisions are loosening and instability. Dual mobility cups were introduced to prevent instability, but their behavior during revisions with acetabular reconstruction has not been assessed. HYPOTHESES: Use of a dual mobility cup cemented in a acetabular reconstruction cage device limits the risk of instability and does not hinder the acetabular fixation during THA revisions. OBJECTIVES: The objective of this study was to test this hypothesis on a retrospective series of 96 revisions. PATIENTS AND METHODS: At a mean follow-up of 41 months (range, 1-101 months), we analyzed a continuous series of 96 revisions using a reconstruction device (70 Kerboull™ cross-plates, six Burch-Schneider™ antiprotrusio cages, 20 custom-fit Novae ARM™ cages associated in all cases with a Novae Stick dual mobility cup cemented into the cage). Fifteen patients died at a mean follow-up of 22 months (range, 1-66 months) and four patients were lost to follow-up at a mean follow-up of 16 months (range, 9-27 months). These were acetabular revisons involving major bone loss, with 62 stage III and 26 stage IV cases on the SOFCOT classification. Eighty-seven patients (87.5%) underwent structural bone allografting. RESULTS: The mean Merle d'Aubigné score increased from 9.6 ± 3.06 (range, 2-16) preoperatively to 15.5 ± 2.32 (range, 7-18) at the follow-up. Ten dislocations (10.4%) occurred, five of which were delayed over three months after the index procedure (5.2%), but there were no intraprosthetic dislocations. At the follow-up, the X-rays showed eight hardware failures, including one cross-plate fracture, one hook fracture, and one flange fracture. Analysis of the radiological position of the cup showed a mean lowering of 15.6mm and a 9.4mm lateralization compared to the preoperative position. One revision for aseptic loosening and another for septic loosening were performed. Taking all-cause acetabular component exchange as a criterion, the survival rate at 8 years was 95.6% (95% CI, 93.3-97.7%) and 99.3% (95% CI, 98.9-99.6%) if the endpoint was aseptic acetabular exchange. DISCUSSION: This study confirms the advantage of dual mobility cups during acetabular reconstruction cemented in antiprotrusio cages as a way to limit, without eliminating, the risk of dislocation. Therefore cemented fixation of dual mobility cups in cages appears to be a reliable short-term option.

Relationship between strength and functional indexes (Rowe and Walch-Duplay scores) after shoulder surgical stabilization by the Latarjet technique.

INTRODUCTION: The rotator cuff muscles help stabilize the glenohumeral joint. Postoperative recovery of rotator cuff muscle strength appears to be an important factor for optimal joint stabilization and the resumption of professional and/or sports activities. OBJECTIVE: To study the relationship between internal rotator (IR) and external rotator (ER) muscle strength, shoulder function and the resumption of sports activities (as typically evaluated with functional scores) following surgical stabilization with the Bristow-Latarjet procedure in cases of chronic shoulder instability. PATIENTS AND METHODS: Twenty patients with anterior, post-traumatic, chronic shoulder instability were included prospectively in a cohort study. The Rowe and Walch-Duplay functional scores were rated for the operated shoulder and the isokinetic IR and ER peak torque values were evaluated with a Con-Trex(®) dynamometer before surgery and then 3, 6 and 21 months afterwards. The isokinetic evaluation was performed (at 180°/s, 120°/s and 60°/s) in the seated position, with the arms in 45° of abduction and 30° of antepulsion in the plane of the scapula. RESULTS: There were no significant postoperative correlations between shoulder function (as judged by the Rowe and Walch-Duplay scores) and IR or ER muscle strength. CONCLUSION: This study did not provide evidence for a correlation between IR and ER muscle strength and functional scores after surgical stabilization of the shoulder. However, it is necessary to objectively measure the rotator cuff strength recovery to adequate the strengthening of rotator muscle prior to the resumption of sports activities. Isokinetic strength assessment may thus be a valuable decision support tool for the resumption of sports activities and would complement the functional scores studied here.

Is nasal carriage of Staphylococcus aureus the main acquisition pathway for surgical-site infection in orthopaedic surgery?

The endogenous or exogenous origin of Staphylococcus aureus, responsible for orthopaedic surgical-site infections (SSI), remains debated. We conducted a multicentre prospective cohort study to analyse the respective part of exogenous contamination and endogenous self-inoculation by S. aureus during elective orthopaedic surgery. The nose of each consecutive patient was sampled before surgery. Strains of S. aureus isolated from the nose and the wound, in the case of SSI, were compared by antibiotypes or pulsed-field gel electrophoresis (PFGE). A total of 3,908 consecutive patients undergoing orthopaedic surgery were included. Seventy-seven patients developed an SSI (2%), including 22 related to S. aureus (0.6%). S. aureus was isolated from the nose of 790 patients (20.2%) at the time of surgery. In the multivariate analysis, S. aureus nasal carriage was found to be a risk factor for S. aureus SSI in orthopaedic surgery. However, only nine subjects exhibiting S. aureus SSI had been found to be carriers before surgery: when compared, three pairs of strains were considered to be different and six similar. In most cases of S. aureus SSI, either an endogenous origin could not be demonstrated or pre-operative nasal colonisation retrieved a strain that was different from the one recovered from the surgical site.

Prevention of dislocation in total hip revision surgery using a dual mobility design.

BACKGROUND: Postoperative dislocation is the commonest complication following revision total hip arthroplasty (THA). HYPOTHESIS AND TYPE OF STUDY: Dual mobility cups are supposed to reduce the risk of THA instability. The present retrospective study tested this hypothesis on revision THAs and also, assessed this design contribution to acetabular fixation longevity. MATERIALS AND METHODS: The series was homogeneous and continuous, comprising a total of 163 revision THAs: 110 of them were bipolar revisions and 53 were restricted to the acetabular component exchange. Mean patient age was 68.7 years (range: 34-92 years). Novae (SERF, Décines) dual mobility cups were used in all cases: 110 cementless cups were used and 53 cups were cemented in a Kerboull reinforcement ring due to severe acetabular bone loss. RESULTS: Mean patients' follow-up (FU) was 60.4 + or - 17.6 months. There were six early dislocations (which were reduced without additional surgery and remained recurrence-free) and two cases of acetabular loosening. The total postoperative dislocation rate at the end of follow-up was 3.7% and the 7-year cup survivorship rate was 96.1% (95% CI: 92.8-99.2%). In revision for aseptic loosening, the instability rate was 2.9%; in the higher instability risk groups (i.e., revision for infection and or recurrent instability) the dislocation rate was respectively 9% and 0%. DISCUSSION: Dual mobility cups provided a dislocation rate of only 3.7% in revision THA, comparable to the one reported with standard implants for primary THA. This kind of cup design is especially suited to deal with high instability risk revision cases, where constrained components are generally recommended. It can also be indicated in cases of aseptic loosening, where it resulted in a 2.9% dislocation rate and only two impending failures of fixation. In terms of mechanical failure rate, these numbers compare well to the ones pertaining to tripolar and constrained implants. These later alternatives remain possible options but are not fully efficient in terms of long-term stability and fixation longevity. LEVEL OF STUDY: Level IV, retrospective or records-based.

Pelvic balance in sagittal and Lewinnek reference planes in the standing, supine and sitting positions.

INTRODUCTION: Sagittal pelvic balance is a recognized factor influencing targeted acetabular-component anteversion during total hip arthroplasty implantation. However, no studies in the literature have systematically reported pelvic parameters data in the standing, sitting and supine positions. HYPOTHESIS: Variations in acetabular cup orientation can be traced to eventual pelvic balance changes in one of these three usual positions. MATERIALS AND METHODS: In these three positions (supine, standing and sitting), pelvic anatomical parameters and reference planes were radiologically defined from a group of 67 patients (average age: 70.2+/-3.2 years). The complete X-rays individual sets were digitized and measurements were obtained by a single operator using a Spineview software (previously, strictly validated for these kind of measurements). Positioning according to the Lewinnek pelvic coordinate system, which is considered as a possible source of errors when vertically standing or horizontally lying, was also investigated. RESULTS: The average pelvic incidence of 59.6 degrees did not vary in the sitting, supine or standing positions, with no statistically significant difference between sexes. The Legaye equation--pelvic incidence is equals to pelvic version plus sacral slope--was verified. Pelvic version increased by an average 22 degrees from the sitting to the supine or standing positions. Sacral slope varied in a reverse order. Pelvic-femoral angle (PFA) decreased by 20 degrees from the standing to the supine position. The Lewinnek plane was located 4 degrees posterior to the vertical plane. Whatever the position adopted, pelvi-Lewinnek angle appeared constant, averaging 12 degrees. DISCUSSION: The average pelvic incidence in this series was high, most probably associated with advancing patient age and/or pathology. The concept of functional anteversion appeared critical when taking into account pelvic version variations (according to the position, sitting, supine or standing) positions. The Lewinnek plane, commonly accepted as the reference plane for hip navigation, was individualised to each patient and should not be mistaken with the vertical plane; positioning of the femur in relation to the Lewinnek plane was also specific to each patient. Cumulative approximation on these two parameters at surgery resulted in a combined imprecision of 26 degrees when standing and 36 degrees when lying down. We have thus defined crucial parameters to be integrated in computer-assisted hip surgery softwares: positional variations of the pelvic version (functional anteversion), positioning of the Lewinnek plane, and PFA value (both specifically patient's dependant). If integration of these parameters into new sofwares versions appears possible, this would represent a reliable compromise between maximum prosthetic stability, maximum joint amplitudes and elimination of possible prosthetic conflict.

Femoral deficiency reconstruction using a hydroxyapatite-coated locked modular stem. A series of 43 total hip revisions.

INTRODUCTION: We report a continuous prospective series of patients operated on for total hip prosthesis femoral component loosening involving a bone defect. Reconstruction was performed using a hydroxyapatite-coated locked modular stem. The study's objective was to assess medium term clinical and X-ray results obtained with this original concept. MATERIALS AND METHODS: The patients included received a REEF (DePuy) femoral implant for aseptic loosening or loosening associated with a periprosthetic fracture. Implantation was systematically accompanied by an extended trochanteric osteotomy (ETO). Patients were followed up prospectively by clinical and X-ray examination. Their loosening was graded at inclusion according to Vives' classification as revised by SOFCOT in 1999. Analysis focused on actuarial implant survivorship, dislocation and the bone/implant interface. RESULTS: Forty-three hips were included: mean follow-up was 58.2 months (12-92) and mean age at surgery was 72.4 years (37-94). The main indications were severe bone loss rated grade III (n=15) or IV (n=16) according to the SOFCOT classification. There was one long-term failure, involving implant fracture secondary to nonunion of the femoral shaft. Mean Postel and Merle d'Aubigné (PMA) clinical assessment score increased from six preoperatively to 14.5 at end of follow-up. X-ray analysis found no stem migration by end of follow-up. There was consistent consolidation of the ETO around the stem, except in one case of stem fracture which evolved into tight nonunion. In terms of metaphyseal integration, five patients showed radiolucency without evolution over follow-up, and eight had severe calcar cortical atrophy at end of follow-up. Mean 5-year actuarial survivorship was 97.7+/-2.3%, with a 2% incidence of dislocation. DISCUSSION: The complications rate was low, and results were comparable with those reported in the literature. The study confirmed the interest of the extended trochanteric osteotomy exposure and the effectiveness of the hydroxyapatite-coated interlocked modular stem concept in the treatment of hip prosthesis loosening with femoral bone loss (involving or not the cortex). On analysis, the one case of failure does not prescribe the surgical technique employed. Implant osseointegration was difficult to analyze. The extent of the surgical approach and of its corresponding sequels, combined with the complexity of adjusting the implant, however, restrict this surgical option indications to level III and IV cases of femoral loosening.

Survival of cementless dual mobility socket with a mean 17 years follow-up.

PURPOSE OF THE STUDY: As part of the 2006 symposium of the French Hip and Knee Society devoted to the dual mobility socket, we report a retrospective multicentric series of 438 first-intention total hip prostheses with a dual mobility socket at a mean 17 years follow-up. The purpose of our report was to ascertain the 15-year survival of this socket and analyze failures. MATERIAL AND METHODS: The series included 438 primary replacements. This was a homogeneous multicentric series. The cementless sockets were 80 Novae-1 titanium Serf cups and 358 Novae-1 stainless steel Serf cups. All stems were inserted without cement: 185 Pf((R)) stainless steel screwed Serf stems, 228 PRO titanium screwed Serf stems, and 25 Corail stems. The mobile polyethylene insert was retaining. All of the heads were 22.2-mm chromium-cobalt heads. Degenerative hip disease was the main etiology and mean follow-up was 17 years (range, 12-20). Mean age at implantation was 54.8 years (range, 23-87). The actuarial method with a 95% confidence interval was used to determine the 15-year cup survival rate. RESULTS: At the last follow-up, none of the patients had presented an episode of early or late instability. Analysis of the socket at last follow-up showed 13 aseptic loosenings, 23 intraprosthetic dislocations, and seven replacements of the polyethylene insert for wear. The overall 15-year prosthesis survival rate was 89.2+/-8.7%. The overall 15-year socket survival rate was 96.3+/-3.7%. DISCUSSION: The fact that, at last follow-up, none of the implants had shown instability confirms the long-term stability of the dual mobility socket. The results in terms of 15-year survival confirm earlier reports. The main cause of failure was cup fixation, which is the weak point of this technique with the initial Novae cup design, which did not have hydroxyapatite coating. The second leading cause was intraprosthetic dislocation, which can be divided into three main categories. The first is intraprosthetic dislocation in a context of pure wear with normal function of the dual mobility socket; the retaining feature of the insert loses its efficacy due to wear. The second category is intraprosthetic dislocation in a context of cup loosening with a third-body effect and increased retention wear, in which case we consider that cup loosening is the primary event leading to rapid secondary wear and subsequent intraprosthetic dislocation. The third category is intraprosthetic dislocation caused by a blockage in a context of fibrosis or impingement involving severe heterotopic ossifications. We had only two femoral failures related to aseptic loosening, most certainly related to use of noncemented implants, which limits the extension of granulomas to the polyethylene. Studying the three series from Saint-Etienne more specifically, where three different configurations were used, it would appear that the titanium cup has a better survival rate and that the titanium used for the thinner necks may be an unfavorable factor for intraprosthetic dislocation.

[Five-year follow-up of a hydroxyapatite coated stem]. / Etude à cinq ans de recul d'une tige anatomique revêtue d'hydroxyapatite.

PURPOSE OF THE STUDY: We studied a cementless anatomic stem combination with a cementless press-fit cup. The purpose of this work was to assess prospectively in a homogeneous consecutive series of patients, the clinical and radiological outcome of this prosthesis at five years follow-up. MATERIAL AND METHODS: The series included 176 hips with a total hip arthroplasty implanted between September 1997 and December 1998 by the same surgeon through an antero-lateral approach (Watson-Jones). We retained for study first intention implantations for primary or secondary joint degeneration. Fractures and revisions were excluded from the analysis. At last follow-up the survival was 93.2%. Patients were revised clinically (satisfaction Harris score). An independent surgeon unaware of the clinical results performed the radiological analysis (Engh and Ara score, Brooker classification). The Kaplan-Meier method was used for the survival curve expressed with 95% confidence interval and considering revision for all causes as failure. RESULTS: The five-year survival of the prosthesis was 98.8%. Clinically, the Harris score varied significantly (p<0.0001) from 32.9+/-1.2 preoperatively to 93.1+/-0.8 at last follow-up. Among the score items, pain exhibited the greatest improvement since at five years only, 10.2% of patients complained of mild pain. Thigh pain, often associated with cementless stems, was very low, 1.3%. Radiologically, the femoral implant was very stable with excellent bone remodelling as illustrated by the high Engh and Ara scores, 20.7+/-0.5 and 5+/-0.2 respectively. Polyethylene wear, 0.075mm/year, was below the usually observed levels. We noted a high rate of heterotopic ossifications, 65.1%, most Brooker I. DISCUSSION: The SPS stem has shown good results at five years, both clinically and radiographically. The objectives of a stable fixation over time and harmonious remodelling appear to be achieved. These promising results should be reexamined in a series with a longer follow-up.