INTRODUCTION: Intervertebral degeneration is characterised by instability due to permanent decrease in the stiffness of the intervertebral segment and concentration of stress upon the posterior portion of the disc, and by morphologic changes in the posterior elements due to posterior displacement of loading, notably enlargement of the lamina and zygapophyseal joints. These changes lead to reduction in the cross-sectional area of the vertebral canal.

In order to counterbalance these changes, an implant has been developed with an interspinous blocker and an artificial ligament made of Dacron. This obviates the need for a permanent fixation in the vertebral bone, avoiding the risk of loosening. Inhibition of hyperextension limits narrowing of the posterior canal, resulting in an increase in its cross-sectional area of up to 40%.

A first-generation implant for nonrigid stabilisation of lumbar segments was developed in 1986 with a titanium interspinous blocker. Following an initial observational study in 1988 and a prospective controlled study from 1988 to 1993, more than 300 patients have been treated for degenerative lesions with significant resolution of residual low back pain with no serious adverse effects.

After careful analysis of the points that could be improved,a second-generation,improved implant called the ‘Wallis implant’ was developed with a redesigned blocker made of PEEK (polyetheretherketone), a more resilient material.

METHODS: Biomechanical studies were used to verify the effectiveness of this implant in increasing intervertebral stiffness, reducing mobility, and unloading the facet joints and the posterior portion of the disc.

A prospective multicenter international observational study was begun a year ago.

RESULTS: Preliminary results confirm the clinical efficacy of this treatment on low back pain and nerve root symptoms, especially in recurrent disc herniation and canal stenosis.

DISCUSSION: Nonrigid intervertebral fixation with the Wallis implant clearly appears to be a useful technique in the management of initial forms of degenerative intervertebral lumbar disc disease. The method should rapidly assume a specific role along with total disc prostheses in the new step-wise surgical strategy to obviate definitive fusion of degenerative intervertebral segments. Moreover, dynamic stabilisation with the Wallis system is totally reversible and leaves all other options open.

Wallis is recommended for patients with lumbar disc disease who have: (i) discectomy for massive herniated disc leading to substantial loss of disc material, (ii) a second discectomy for recurrence of herniated disc, (iii) discectomy for herniation of a transitional disc with sacralization of L5, (iv) degenerative disc disease at a level adjacent to a previous fusion or prosthesis, (v) isolated disc resorption, notably with concomitant type-1 Modic changes, associated with low back pain, or (vi) symptomatic narrow canal treated by resection of the superior aspect of the laminae.

Aims

Plating displaced proximal humeral fractures is associated with a high rate of screw perforation. Dynamization of the proximal screws might prevent these complications. The aim of this study was to develop and evaluate a new gliding screw concept for plating proximal humeral fractures biomechanically.

Purpose: Instability of the injured elbow early after repair can lead to recurrent dislocation or failed fixation. Complementary immobilisation increases the risk of stiffness. The purpose of this study was to assess the contribution of dynamic external fixation which allows protected mobilisation and controlled distraction. We wanted to determine feasibility and appropriate indications. Material and methods: We used the Pennig articulated elbow fixator in twelve trauma victims. Most had complex injuries: five dislocations with lesions of the medial ligaments and fractures of the radial head, including two with early recurrent dislocation; five joint fractures (involving to various degrees the lateral condyle, the head of the radius, the olecranon, and the humeral surface). This fixation method was also used for old or sequelar lesions to achieve reconstruction of the humeral surface (n=3) or after extensive arthrolysis (n=2). Mobilisation was started on day five postop. Results: For the fresh injuries, the humero-ulnar articulation was centred in all cases. In these patients, mean final flexion was 0.35.130° and pronation-supination was 0.10.155°. One purely lateral dislocation was observed. Radio-ulnar synostosis after fracture of the ulna (n=1) and osteoma (n=1) were also observed. Discussion: This dynamic external fixation system is a simple and safe procedure if a rigorous technique is applied. This method enabled early rehabilitation without secondary displacement and also enabled reliable contention particularly important in these multiple injury patients. The patients experienced very little pain during rehabilitation exercises, probably due to the distraction which did not appear to provoke reflex dystrophy. For complex instability of the elbow, the reduction of stress forces during mobilisation movements enables an extension of the indications for preservation of the joint fragments. Less reliable results are obtained for stiff elbows with old lesions

We examined the effect of periosteal devascularisation upon the early healing of osteotomies of sheep tibiae held in an instrumented external fixation system with an axial stiffness of 240 N/mm. At 14 days, cortical blood flow measured by the microsphere technique was 19.3 ml/min/100g in the well-vascularised osteotomies, but only 1.7 ml/min/100g in the devascularised osteotomies, despite an increase in medullary flow (p less than 0.0005). Delay in healing of the devascularised osteotomies was suggested by an in vivo monitoring system and confirmed by post-mortem mechanical testing. We suggest that the osteogenic stimulus of dynamic external fixation is dependent on the early restoration of cortical blood flow in devascularised fractures

Pain, stiffness, instability and degenerative arthritis are common sequelae of complex fracture-dislocations of the proximal interphalangeal (PIP) joint. Operations were carried out to obtain stability, followed by application of a dynamic external fixator in 20 patients with a mean age of 29 years. This provided stability and distraction, and allowed controlled passive movement. Most (70%) of the patients had a chronic lesion and the mean time from injury to surgery was 215 days (3 to 1953). The final mean range of movement was 12 to 86°.

Complications included redislocation and septic arthritis, which affected the outcome. Four pin-track infections and two breakages of the hinge did not influence the result. The PIP Compass hinge is a useful adjunct to surgical reconstruction of the injured PIP joint.

Aims: The purpose of this study is to support the possibility of a satisfactory articular congruity of the radiocarpal articulation, maintenance of the reduction of an unstable fracture of the distal part of the radius and early motion of the wrist with restoration of the radial length, after dynamic external þxation. Methods: From January 1997 to 2002, 95 matured patients who had 77 comminuted unstable fractures of the distal part of the radius were treated with a dynamic external-þxation device in the Hospital of Caserta and the Clinic of Maddaloni. Mobilisation of the wrist from 0 Ð 30 degrees of ßexion was begun at approximately two weeks and full motion, allowing 30 degrees of extension, was started at approximately four weeks. After having checked with radiographs and clinical examinations, all patients were classiþed by Frykmanñs criteria and included in our study. Then they were evaluated as described by Sarmiento, Gartland and Werley on radiographs and subjective and objective elements. Results: Outcomes after one year were excellent or good in 91% of patients and no more complications were observed. Conclusions: The main goal of treatment is the restoration of the anatomical alignment and the positioning of the fragments so as to allow early motion of the joints. We believe in this method of þxation and on the basis of our data we can recommend it for improvement of early mobility of the wrist, and to prevent osteoarthrosis and disuse osteopenia.

Femoral neck fractures account for half of all hip fractures and are recognized as a major public health problem associated with a high socioeconomic burden. Whilst internal fixation is preferred over arthroplasty for physiologically younger patients, no consensus exists about the optimal fixation device yet. The recently introduced implant Femoral Neck System (FNS) (DePuy Synthes, Zuchwil, Switzerland) was developed for dynamic fixation of femoral neck fractures and provides angular stability in combination with a minimally invasive surgical technique. Alternatively, the Hansson Pin System (HPS) (Swemac, Linköping, Sweden) exploits the advantages of internal buttressing. However, the obligate peripheral placement of the pins, adjacent to either the inferior or posterior cortex, renders the instrumentation more challenging. The aim of this study was to evaluate the biomechanical performance of FNS versus HPS in a Pauwels II femoral neck fracture model with simulated posterior comminution. Forty-degree Pauwels II femoral neck fractures AO 31-B2.1 with 15° posterior wedge were simulated in fourteen paired fresh-frozen human cadaveric femora, followed by instrumentation with either FNS or HPS in pair-matched fashion. Implant positioning was quantified by measuring the shortest distances between implant and inferior cortex (DI) as well as posterior cortex (DP) on anteroposterior and axial X-rays, respectively. Biomechanical testing was performed in 20° adduction and 10° flexion of the specimens in a novel setup with simulated iliopsoas muscle tension. Progressively increasing cyclic loading was applied until construct failure. Interfragmentary femoral head-to-shaft movements, namely varus deformation, dorsal tilting and rotation around the neck axis were measured by means of motion tracking and compared between the two implants. In addition, varus deformation and dorsal tilting were correlated with DI and DP. Cycles to 5/10° varus deformation were significantly higher for FNS (22490±5729/23007±5496) versus HPS (16351±4469/17289±4686), P=0.043. Cycles to 5/10° femoral head dorsal tilting (FNS: 10968±3052/12765±3425; HPS: 12244±5895/13357±6104) and cycles to 5/10° rotation around the femoral neck axis (FNS: 15727±7737/24453±5073; HPS: 15682±10414/20185±11065) were comparable between the implants, P≥0.314. For HPS, the outcomes for varus deformation and dorsal tilting correlated significantly with DI and DP, respectively (P=0.025), whereas these correlations were not significant for FNS (P≥0.148). From a biomechanical perspective, by providing superior resistance against varus deformation and performing in a less sensitive way to variations in implant placement, the angular stable Femoral Neck System can be considered as a valid alternative to the Hansson Pin System for the treatment of Pauwels II femoral neck fractures

Nearly one quarter of ankle fractures have a recognized syndesmosis injury. An intact syndesmosis ligament complex stabilizes the distal tibio-fibular joint while allowing small, physiologic amounts of relative motion. When injured, malreduction of the syndesmosis has been found to be the most important independent factor that contributes to inferior functional outcomes. Despite this, significant variability in surgical treatment remains. This may be due to a poor understanding of normal dynamic syndesmosis motion and the resultant impact of static and dynamic fixation on post-injury syndesmosis kinematics. As the syndesmosis is a dynamic structure, conventional CT static images do not provide a complete picture of syndesmosis position, giving potentially misleading results. Dynamic CT technology has the ability to image joints in real time, as they are moved through a range-of-motion (ROM). The aim of this study was to determine if syndesmosis position changes significantly throughout ankle range of motion, thus warranting further investigation with dynamic CT. This is an a priori planned subgroup analysis of a larger multicentre randomized clinical trial, in which patients with AO-OTA 44-C injuries were randomized to either Tightrope or screw fixation. Bilateral ankle CT scans were performed at 1 year post-injury, while patients moved from maximal dorsiflexion (DF) to maximal plantar flexion (PF). In the uninjured ankles, three measurements were taken at one cm proximal to the ankle joint line in maximal DF and maximal PF: Anterior (ASD), middle (MSD), and posterior (PSD) syndesmosis distance, in order to determine normal syndesmosis position. Paired samples t-tests compared measurements taken at maximal DF and maximal PF. Twelve patients (eight male, six female) were included, with a mean age of 44 years (±13years). The mean maximal DF achieved was 1-degree (± 7-degrees), whereas the mean maximal PF was 47-degrees (± 8-degrees). The ASD in DF was 3.0mm (± 1.1mm) versus 1.9mm (± 0.8mm) in PF (p<0.01). The MSD in DF was 3.3mm (±1.1mm) versus 2.3mm (±0.9mm) in PF (p<0.01). The PSD in DF was 5.3mm (±1.5mm) versus 4.6mm (±1.9mm) in PF (p<0.01). These values are consistent with the range of normal parameters previously reported in the literature, however this is the first study to report the ankle position at which these measurements are acquired and that there is a significant change in syndesmosis measurements based on ankle position. Normal syndesmosis position changes in uninjured ankles significantly throughout range of motion. This motion may contribute to the variation in normal anatomy previously reported and controversies surrounding quantifying anatomic reduction after injury, as the ankle position is not routinely standardized, but rather static measurements are taken at patient-selected ankle positions. Dynamic CT is a promising modality to quantify normal ankle kinematics, in order to better understand normal syndesmosis motion. This information will help optimize assessment of reduction methods and potentially improve patient outcomes. Future directions include side-to-side comparison using dynamic CT analysis in healthy volunteers

Three Cannulated Screws (3CS), Dynamic Hip Screw (DHS) with antirotation screw (DHS–Screw) or with a Blade (DHS–Blade) are the gold standards for fixation of unstable femoral neck fractures. Compared to 3CS, both DHS systems require larger skin incision with more extensive soft tissue dissection while providing the benefit of superior stability. The newly designed Femoral Neck System (FNS) for dynamic fixation combines the advantages of angular stability with a less invasive surgical technique. The aim of this study is to evaluate the biomechanical performance of FNS in comparison to established methods for fixation of the femoral neck in a human cadaveric model. Twenty pairs of fresh–frozen human cadaveric femora were instrumented with either DHS–Screw, DHS–Blade, 3CS or FNS. A reduced unstable femoral neck fracture 70° Pauwels III, AO/OTA31–B2.3 was simulated with 30° distal and 15° posterior wedges. Cyclic axial loading was applied in 16° adduction, starting at 500N and with progressive peak force increase of 0.1N/cycle until construct failure. Relative interfragmentary movements were evaluated with motion tracking. Highest axial stiffness was observed for FNS (748.9 ± 66.8 N/mm), followed by DHS–Screw (688.8 ± 44.2 N/mm), DHS–Blade (629.1 ± 31.4 N/mm) and 3CS (584.1 ± 47.2 N/mm) with no statistical significances between the implant constructs. Cycles until 15 mm leg shortening were comparable for DHS–Screw (20542 ± 2488), DHS–Blade (19161 ± 1264) and FNS (17372 ± 947), and significantly higher than 3CS (7293 ± 850), p<0.001. Similarly, cycles until 15 mm femoral neck shortening were comparable between DHS–Screw (20846 ± 2446), DHS–Blade (18974 ± 1344) and FNS (18171 ± 818), and significantly higher than 3CS (8039 ± 838), p<0.001. From a biomechanical point of view, the Femoral Neck System is a valid alternative to treat unstable femoral neck fractures, representing the advantages of a minimal invasive angle–stable implant for dynamic fixation with comparable stability to the two DHS systems with blade or screw, and superior to Three Cannulated Screws

INTRODUCTION. The elimination of motion and disc stress produced by spinal fusion may have potential consequences beyond the index level overloading the spinal motion segments and leading to the appearance of degenerative changes. So the “topping-off” technique is a new concept instructing dynamic fixation such as interspinous process device (IPD) for the purpose of avoiding adjacent segment disease (ASD) proximal to the fusion construct. MATERIALS AND METHODS. The study simulated spinal fusion in L4-L5, fusion combined DIAM in L3-L4. The ROM and maximum von Miss stresses were analyzed in flexion, extension, lateral bending, and torsion in response to hybrid method, compared to intact modeland fusion model. RESULTS. The investigation revealed that decreased ROM, intradiscal stress in implanted level but a considerable increase in stresses at more upper level (L2-L3) during flexion and extension in hybrid model, comparing with the fusion model. CONCLUSIONS. The raise of intradiscal pressure at the adjacent segment to a rigid fusion segment can be reduced when the rigid construct is augmented with an interspinous process device. However, the burden of stress over total spinal segments was still the same, the stress and ROM were just shift to supraadjacent levels

Aims

Fixation techniques used in the treatment of slipped capital femoral epiphysis (SCFE) that allow continued growth of the femoral neck, rather than inducing epiphyseal fusion in situ, have the advantage of allowing remodelling of the deformity. The aims of this study were threefold: to assess whether the Free-Gliding (FG) SCFE screw prevents further slip; to establish whether, in practice, it enables lengthening and gliding; and to determine whether the age of the patient influences the extent of glide.

Aims

The ideal management of acute syndesmotic injuries in elite athletes is controversial. Among several treatment methods used to stabilize the syndesmosis and facilitate healing of the ligaments, the use of suture tape (InternalBrace) has previously been described. The purpose of this study was to analyze the functional outcome, including American Orthopaedic Foot & Ankle Society (AOFAS) scores, knee-to-wall measurements, and the time to return to play in days, of unstable syndesmotic injuries treated with the use of the InternalBrace in elite athletes.

Introduction. Ankle fusion presents a difficult problem in the presence of infection, inadequate soft tissue, poor bone stock and deformity. Nonunion and infection remains a problem even with internal fixation. Ilizarov frame provides an elegant solution to the problem with stable remote fixation while allowing lengthening, deformity correction and weight bearing. Patients and methods. Twenty-one consecutive patients were studied. The mean age at onset of disease was 52 years (range 4-70). Mean duration of the problem was 59.9 months (6-372). Aetiology included traumatic arthritis in 5, traumatic arthritis with osteomyelitis in 1, failed ankle fusion in 8, septic arthritis in 1, infected ankle fracture nonunion in 1, avascular necrosis of talus in 1, congenital deformity in 3 and failed ankle arthroplasty in 1. 15 patients had deformity of the ankle at the time of presentation. 15 of the 21 patients had either clinical or radiological evidence of infection. Treatment principles involved local excision, deformity correction with good alignment and soft tissue management. Static Compression was achieved with an Ilizarov frame while dynamic fixation was performed in 3 cases for lengthening. Antibiotics treatment was continued until union in the infected cases. On achieving union the frame was removed and a below knee cast was applied for 4 weeks. Results. Fusion was achieved in all cases at an average time of 5 months. One patient had below knee amputation for chronic pain. There was no recurrence of infection. Complications included pin site infection, lateral impingement, drug reaction and hind-foot pain. The results were assessed in terms of SF36 and Modified foot and ankle score. Conclusion. The Ilizarov ankle fusion is a reliable salvage procedure in difficult ankle problems

The results obtained with a lightweight dynamic axial fixator in the treatment of fractures are reported. The apparatus comprises a single bar with articulating ends which clamp self-tapping screws and can be locked at an angle appropriate for axial alignment. A telescopic facility allows ready conversion from rigid to dynamic fixation once periosteal callus formation has commenced. Reduction and controlled distraction or compression are achieved by means of a detachable compressor unit. We treated 288 patients with fresh fractures and 50 with ununited fractures. The success rate for fresh fractures was 94%, with average healing times ranging from 3.4 to 6.5 months. In ununited fractures also, the success rate was 94% with average healing times ranging from 4.7 to 6.5 months. Complications were minimal. The device is versatile and can be applied in an average of 15 minutes. It permits ambulatory fracture care without sacrificing a sound anatomical result

Aims

In a randomized controlled trial with two-year follow-up, patients treated with suture button (SB) for acute syndesmotic injury had better outcomes than patients treated with syndesmotic screw (SS). The aim of this study was to compare clinical and radiological outcomes for these treatment groups after five years.

We enrolled 34 normal volunteers to test the hypothesis that there were two types of movement of the wrist. On lateral radiographs two distinct patterns of movement emerged. Some volunteers showed extensive rotation of the lunate with a mean range of dorsiflexion of 65°, while others had a mean range of 50°. The extensive rotators were associated with a greater excursion of the centre of articulation of the wrist. It is suggested that dynamic external fixation of a fracture of the distal radius carries with it the risk of stretching the ligaments or causing volar displacement at the site of the fracture

We describe a technique for slow, progressive, symmetrical distraction of the growth plate using a lightweight dynamic axial fixation system. Results are given for the elongation of 40 bony segments in children with limb-length discrepancies and 60 segments in children with achondroplasia or hypochondroplasia. Increases in limb length of up to 36% were obtained in non-achondroplastic and up to 64.5% in achondroplastic patients. There were no nerve or vascular lesions or bony infections and no case required a bone graft. Pin-track complications occurred in only 1.5%

Introduction and Aims: Eight thousand Duraloc 300 cups were implanted worldwide in 2002. To our knowledge, no 10-year results have been published to date. We undertook this study to ascertain whether this optimism was justified. Method: One hundred consecutive total hip replacements using a Duraloc 300 cup were reviewed at a minimum of 10 years. Post-operative x-rays were analysed for cup placement and interface gaps. Follow-up films were analysed for lucent lines, osteolysis, wear and migration. Kaplan-Meier survivorship analysis was performed. Results: All components were found to be stable with no evidence of loosening or migration. The mean rate of wear was 0.12mm per year. Three hips developed pelvic osteolysis in zone 2 at the level of the apex hole, of which two have successfully undergone a bone grafting procedure and one patient is awaiting surgery. Conclusion: The Duraloc 300 cup has excellent 10-year results with no cases of loosening. There was a low incidence of pelvic osteolysis. Cementless fixation provides dynamic biological fixation, which is continuously renewed with the passage of time. There is no reason to believe that the durability of fixation will not extend well beyond 10 years

Introduction: We prospectively followed all hip fracture patients admitted between 2004–2006, identified cases where the intention was to treat conservatively and compared their functional outcome and mortality with a similar cohort treated surgically over the same period. Methods: We recorded length of hospital stay, place of discharge, pre and post-fracture mobility and residence, 30 day and 1 yr mortality, re-admission and delayed surgery. The group treated surgically was recruited and matched for age, gender, pre and post fracture mobility, mental confusion and independence with the conservatively treated group. Results: 25 patients were treated conservatively. 22 patients treated surgically over the same period were recruited. The mean hospital stay was 13 days in both groups. There were 4 extracapsular (3 displaced) and 21 intracapsular fractures (5 displaced) in the conservative arm and 11 extracapsular and 9 intracapsular fractures in the surgically treated arm. 4 patients from the conservative treatment group underwent late surgery 20 days – 2 months after the index event. Surgically treated group had 11 dynamic screw fixation, 1 cannulated screw, 1 total hip replacement and 7 hemiarthroplasty. 9/14 of the conservatively treated patients were mobile independently or with aid after treatment compared to 11/16 patients after surgery. 7/16 patients treated conservatively were living independently in their own residence, compared to 10/14 patients in the operatively treated patients. 1 month and 1 year mortality in conservatively treated group was 4/21 and 7/21 respectively compared to 1/20 and 5/20 in the operative fixation group. There was no statistically significant difference in mobility, residence or mortality between the two groups (Fisher exact test, p > 0.05). Discussion: Conservative management after hip fracture in medically unfit patients does not result in statistically significant difference in functional outcome or mortality compared to patients treated surgically