P. Boyer

Endoscopically assisted reconstruction of acute acromioclavicular joint dislocation using a synthetic ligament. Outcomes at 12 months.

OBJECTIVES The treatment for acute acromioclavicular (AC) joint dislocation remains controversial because of the elevated level of complications and related morbidity. The objective of this study was to evaluate clinical outcomes, radiographic results, and the complications after arthroscopic stabilization of acute stages III or IV (Rockwood classification) acromioclavicular dislocations. MATERIAL AND METHODS Sixteen patients (15 males and one female) found to have Rockwood stage III or IV AC joint dislocation were operated. All the patients were stabilized arthroscopically with a synthetic ligament placed between the clavicle and the coracoid. The application of the synthetic ligament reduced the dislocation and stabilized the AC joint, allowing healing of the coracoacromial ligament. Results were assessed clinically (Constant score) and radiographically before and a mean 12 months after the treatment. RESULTS Despite the excellent clinical results at the last follow-up both in terms of the Constant score (mean, 91 points; range, 60-100) and patient satisfaction, two patients required revision surgery while some had pain over the clavicular button. The X-rays showed three cases of partial loss of reduction due to distal migration of the flip button. DISCUSSION Arthroscopically assisted treatment of acute AC joint dislocation is advantageous because it provides good clinical results and few complications. The rate of recurrence and the postoperative loss of reduction requires better definition of the indications and improvement of the surgical implants and technique. LEVEL OF EVIDENCE Level IV. Prospective cohort study.

Efficacy of intra-tendinous injection of platelet-rich plasma in treating tendinosis: comprehensive assessment of a rat model

ObjectivesTo assess the potential of intra-tendinous injection of platelet rich plasma (PRP) to treat tendinosis (T+) in a rat model of patellar and Achilles T+, and evaluate its local toxicity.MethodsThirty rats (120 patellar and Achilles tendons) were used. We induced T+ into 80 tendons (patellar = 40, Achilles = 40) by injecting collagenase at day 0 under ultrasound (US) guidance. Clinical examination and US at day 3, followed by US-guided intra-tendinous injection of either PRP (PRPT+, n = 40) or physiological serum (ST+, n = 40, control). Follow-up was at days 6, 13, 18 and 25 using clinical, US and histological evaluation. To study PRP toxicity, we injected PRP into 40 normal tendons (PRPT-) and compared with 40 untreated normal tendons (T-).ResultsAll PRPT+ showed better joint mobilisation compared with ST+ at day 6 (P = 0.005), day 13 (P = 0.02), day 18 (P = 0.003) and day 25 (P = 0.01). Similar results were found regarding US and histology, with smaller collagen fibre diameters (day 6, P = 0.003, day 25, P ≤ 0.004), less disorganisation and fewer neovessels (day 6, P = 0.003, day 25, P = 0.0003) in PRPT+ compared with ST+. Comparison between PRPT- and T- showed no PRP toxicity (P = 0.18).ConclusionsOur study suggests that mono-injection of PRP in T+ improves tendon healing, with no local toxicity.Key Points• We assessed the potential of platelet rich plasma (PRP) to treat tendinosis.• We treated patellar and Achilles tendinosis in a rat model.• We evaluated clinical, imaging and histological data.• Intra-tendinous PRP injection could be useful in the treatment of tendinosis.

Does fibrin sealant use in total knee replacement reduce transfusion rates? A non-randomised comparative study.

BACKGROUND Studies assessing fibrin sealants use during total knee replacement (TKR) have produced inconsistent results. We evaluated fibrin sealant therapy in TKR procedures performed without tourniquet and without postoperative drains. HYPOTHESIS Use of a fibrin sealant during TKR decreases calculated total blood loss, thereby diminishing blood transfusion requirements and costs. PATIENTS AND METHODS We studied 62 patients with primary knee osteoarthritis who underwent TKR by the same surgeon between September 2009 and December 2010. Fibrin sealant was used only in the last 31 patients, who were compared to the first 31 patients regarding calculated total blood loss, blood transfusion rate, and mean number of red-blood-cell units used per patient. Costs were compared in the two groups. RESULTS In the control group, mean total blood loss calculated using the method of Gross was 1.3±0.6 L, 48% of patients required blood transfusions, and the mean number of units per patient was 0.9±1. In the fibrin-sealant group, 29% of patients required blood transfusions and the mean number of units was 0.6±0.9. The between-group differences in favour of the fibrin-sealant group were not statistically significant. In each group, compared with patients not requiring blood transfusions, patients needing transfusions had significantly lower starting preoperative haemoglobin values and a significantly greater positive difference between the calculated total blood loss and the maximum allowable blood loss. In the test group, the cost of the 31 units of fibrin sealant was 9743€ and the cost reduction due to using 11 fewer red-blood-cell units was only 3484€. Hospital stay was not significantly shorter in any of the two groups. DISCUSSION Blood transfusion minimisation during TKR should rely chiefly on correcting preoperative anaemia and optimizing transfusion decisions based on the difference between the total blood loss and the maximum allowable blood loss. Fibrin sealant did not significantly diminish transfusion requirements in our study. Randomised studies in larger patient populations are needed. The cost of fibrin sealant may exceed the expected cost savings in relation with decreased blood transfusion requirements. LEVEL OF EVIDENCE Level III (before-after therapeutic study).

Navigated revision knee arthroplasty using a system designed for primary surgery.

While navigation is now recognized as an efficient tool for improving femoro-tibial alignment of primary knee prostheses, its use in revision surgery has not yet been fully evaluated. We describe a procedure based on a bone morphing acquisition performed on the surface of the original implants, followed by a dependant bone cut sequence (tibia first). Using the current system, a preoperative CT-scan measurement of the original femoral component was required. Knee balancing was achieved using spacer blocks, with the trial tibial component and the original femoral component still in place. Preliminary experience from 19 cases, some with severe bone loss requiring reconstruction, is reported. A retrospective comparison to 10 non-navigated revision cases performed concomitantly by the same operating surgeon was carried out. Although there was no significant difference in the number of outliers for the two series, navigation appeared to be a valuable aid in reconstructing both bone extremities, while controlling the level of the joint line. However, definitive validation requires further prospective and comparative investigations in larger series.

Arthroscopic treatment of acute acromioclavicular dislocations using a double button device: Clinical and MRI results

INTRODUCTION Arthroscopic treatment of acute grade 3 and 4 acromioclavicular dislocation is controversial, due to the risk of recurrence and of postoperative reduction defect. The purpose of the present study was to investigate whether the healing of the acromioclavicular (AC) and coracoclavicular (CC) ligaments and the accurate 3D positioning parameters of the AC joint using MRI were correlated with satisfactory functional outcome. MATERIAL Thirty-nine patients were enrolled from 2009 to 2011 and managed arthroscopically by CC lacing using a double-button device. METHODS Clinical assessment included the Shoulder and Hand (QuickDash) score, Constant-Murley score and visual analog scale (VAS) for residual pain. Time and rate to return to work and return to sport were assessed according to type of sport and work. Postoperative complications were recorded. Radiological examination consisted of anteroposterior clavicle and lateral axillary radiographs. AC ligament healing and 3D joint congruency were assessed on MRI and correlated to the clinical results. RESULTS Mean patient age was 35.7 years (range, 20-55). Mean follow-up was 42.3±10.6 months (range, 24-60). At final follow-up, mean QuickDash score, Constant score and VAS were respectively 1.7±4 (range, 0-11), 94.7±7.3 (range, 82-100) and 0.5±1.4 (range, 0-2). Thirty-five (90%) patients were able to resume work, including heavy manual labor, and sport. Radiology found accurate 3D joint congruency in 34 patients (87%) and CC and AC ligament healing in 36 (93%). Complications included reduction loss at 6 weeks in 3 patients, requiring surgical stabilization. Satisfactory functional results were associated with accurate AC joint congruency in the coronal and axial planes (P<0.05) and good AC and CC ligament healing (P<0.04). An initial 25% reduction defect in the coronal plane was not associated with poor functional results (P=0.07). CONCLUSION Arthroscopic treatment by CC lacing satisfactorily restored ligament and joint anatomy in the present series. These satisfactory anatomic results correlated with good clinical outcome encourage continuing with this technique. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Intra-operative navigation of knee kinematics and the influence of osteoarthritis

Intra-operative assessment of knee kinematics should optimise implantation of total knee arthroplasties. The purpose of this work was to validate the data delivered by an adapted navigation system in 10 healthy cadaver knees and to investigate the kinematics of 10 osteoarthritic (OA) knees in patients undergoing total knee replacement. The system displayed the magnitude of axial rotation, the position of the instantaneous centre of axial rotation and the displacements of the condyles. Successive cycles from full extension to 140° of flexion in the same knee produced a mean external rotation of 20° ± 10°, which was correlated to knee flexion (r=0.6 ± 0.2 in healthy knees, r=0.8 ± 0.2 in OA knees). The centre of axial rotation migrated posteriorly an average of 8.2mm in both groups. The posterior displacements were 4 mm ± 5 mm in healthy and 5 mm ± 6 mm in OA knees for the medial condyle, and 21 mm ± 9 mm in healthy and 21 mm ± 10 mm in OA knees for the lateral condyle. The medial condyle lifted off beyond 110° of flexion. Results in healthy knees were consistent with those reported in the current literature. The kinematics of healthy and of OA knees with an intact anterior cruciate ligament did not differ significantly.

Medium-term osteolysis with the Wallaby I ® deep-dished total knee prosthesis

BACKGROUND Highly congruent total knee prostheses were introduced in the 1990s in the hope of decreasing polyethylene wear, thereby minimising loosening and particle-induced peri-prosthetic osteolysis. Despite promising long-term outcomes, substantial rates of aseptic loosening were reported with conventional gamma-irradiated polyethylene inserts, suggesting that highly reticulated polyethylene should be used instead. We assessed medium-term outcomes of the Wallaby I® total knee prosthesis with a deep-dished tibial insert made of conventional gamma-irradiated polyethylene. HYPOTHESIS We hypothesised that the deep-dished Wallaby I® prosthesis was associated with similar or lower rates of aseptic loosening and peri-prosthetic osteolysis compared to posterior-stabilised prostheses. MATERIALS AND METHODS At our institution, 121 consecutive patients underwent total knee arthroplasty (TKA) with a deep-dished cemented prosthesis (Wallaby I®, Sulzer/Centerpulse, Zürich, Switzerland) between 2001 and 2005. Among them, 89 had complete follow-up data over a 4-year period and a mean follow-up of 96 months. We retrospectively analysed the clinical and radiographic IKS scores in these 89 patients. RESULTS Osteolysis with aseptic loosening required revision TKA of 10 knees after a mean follow-up of 81 months. Mean 9-year prosthesis survival was 88±17%. Four inserts exhibited evidence of delamination. A fracture of the postero-medial aspect of the tibial baseplate beneath a zone of insert wear was found in 1 knee and gross mobility of the insert on the baseplate in 6 knees. The other 79 patients had good clinical and radiographic outcomes with a mean range of active knee flexion of 108±15°. DISCUSSION The medium-term outcomes in our study were inferior to those reported with posterior-stabilised tibial components. Sporadic variations in polyethylene quality may explain the cases of osteolysis (shelf oxidation). In addition, the increased shear stresses related to the deep-dish design may increase backside wear, thereby compromising insert fixation to the baseplate. We believe the Wallaby I® prosthesis should no longer be used, and we recommend computed tomography follow-up of patients harbouring this prosthesis. LEVEL OF EVIDENCE Level IV (retrospective study).

Does the PFNA™ nail limit impaction in unstable intertrochanteric femoral fracture? A 115 case-control series

INTRODUCTION Femoral neck shortening after dynamic fixation of extra-capsular fracture may impair functional results, but is rarely assessed. The present study measured impaction in stable and unstable fractures (on the Ender classification) treated by PFNA™ nail. The objectives were: 1) to validate the Ender classification to assess fracture stability; 2) to determine whether neck shortening and head purchase quality varied with stability; and 3) to determine the functional impact of femoral neck shortening. HYPOTHESIS The study hypothesis was that the PFNA™ nail stabilizes unstable as well as stable fractures. MATERIALS AND METHODS One hundred and fifteen consecutive patients, aged over 70 years, operated on for intertrochanteric fracture using the PFNA™ nail were followed up prospectively for 6 months. Multivariate analysis, including age, gender, assembly quality and body-mass index, was applied to assess the predictive power of the Ender classification with respect to femoral neck shortening. Secondly, patients were grouped according to stable versus unstable fracture (n=70 and 45, respectively), and impaction and femoral head purchase were assessed on a dedicated radiographic protocol. Functional results were assessed on Parker score. RESULTS In the unstable fracture group, 3 assembly failures required revision by total hip replacement. Ender grade>2 was significantly predictive of>5mm neck shortening. Neck shortening was greater in unstable fracture: 8.1 ± 8.4mm (range, 4-32 mm), versus 2.5 ± 3.7 mm (range, 3-14 mm) (P=0.0004). Mean blade cut-through was 1.2 ± 2.9 mm (range, 1-12 mm) in unstable fracture, versus 0.3 ± 1.3 mm (range, 1-6mm) (P=0.02). Mean cut-out was 2.3 ± 6 mm (range, 2-21 mm) in unstable fracture, versus 0.5 ± 2.6 mm (range, 1-8mm) (P=0.03). Parker scores diminished comparably in the two groups, without significant difference at follow-up: 3.9 ± 2.6 (range, 0-9) in stable and 3.1 ± 1.9 (range, 0-8) in unstable fracture; reduction in Parker score showed no correlation with femoral neck shortening (r=0.013, P=0.88). DISCUSSION The PFNA™ nail provides poorer stabilization of unstable compared to stable fracture. Femoral neck shortening should be taken into account in assessing internal fixation hardware perfomances. LEVEL OF EVIDENCE Level III. Prospective case-control study.

Initial disc structural preservation in type A1 and A3 thoracolumbar fractures

PURPOSE Despite a sizable amount of literature, the optimal management of thoracolumbar fractures remains controversial and many authors assume the existence of disc lesions in Magerl type A fractures. The purpose of the study was to assess the intervertebral discs in these fractures at the time of trauma. The hypothesis was that there was no change in shape and signal intensity of the discs initially. METHODS Fifty-one patients diagnosed with 87 types A1 and A3 thoracolumbar fractures were enrolled in a prospective study. MRI analysis involved evaluation of disc signal, height and morphological modifications according to Oners classification. RESULTS No signal intensity modification was identified on MRI. Disc morphology was either normal or altered with creeping of discal tissue in the vertebral endplate depression. Overall, 98% of the discs were either type 1 or type 3. Mean disc height on MRI was 1.03 ± 0.36 initially. CONCLUSIONS In this study, MRI showed that no loss of height occurred in discs adjacent to fractured vertebra and that there was no major alteration of the disc in terms of signal intensity and morphology. Therefore, the intervertebral disc should not be removed in Magerl type A fractures. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Removal of infected cemented hinge knee prostheses using extended femoral and tibial osteotomies: Six cases

Extended femoral and tibial osteotomies were performed to remove infected cemented hinged knee prostheses in five patients (six knees) with a mean age of 72 years (44-85) and a history of multiple knee surgeries. A tibial osteotomy was used to mobilise the distal quadriceps insertion and to release the tibial extension. The femoral component was extracted by downward traction and its cement mantle was cleared through an anterior osteotomy (n=4) or via the distal approach (n=2). The bone flaps were re-approximated by wire cerclage over articulating acrylic spacers. Mean time to re-implantation of a new knee prosthesis was 11 months (6-24). Revision prostheses with cement fixation restricted to the epiphyseal-metaphyseal region were used. Infection recurred in two cases at 16 and 4 months after the prosthetic re-implantation, and was managed by joint fusion for one and irrigation/lavage for the other, respectively. At last follow-up after a mean of 53 months, the mean Parker score was 4 ± 2, the mean IKS knee score was 66 ± 25 (28-93), and the mean IKS function score was 7 ± 16 (0-40). This technique facilitates the removal of infected cemented components of hinge prostheses and of the cement mantle, most notably in the absence of loosening, without compromising re-implantation of a new knee prosthesis.