Background

Overlooked compartment syndrome represents a devastating complication for the patient. Invasive compartment pressure measurement continues to be the gold standard. However, repeated measurements in uncertain cases may be difficult to achieve. We developed a new, noninvasive method to assess tissue firmness by pressure related ultrasound.

Adequate perpendicular access to the posterolateral talar dome for osteochondral defect repair is difficult to achieve and a number of different surgical approaches have been described. This cadaveric study examined the exposure available from various approaches to help guide pre-operative surgical planning. Four surgical approaches were performed in a step-wise manner on 9 Thiel-embalmed cadavers; anterolateral approach with arthrotomy, anterolateral approach with anterior talo-fibular ligament (ATFL) release, anterolateral approach with antero-lateral tibial osteotomy, and anterolateral approach with lateral malleolus osteotomy. The furthest distance posteriorly which allowed perpendicular access with a 2mm k-wire to the lateral surface of the talar dome was measured from the anterior aspect of the talar dome. The mean antero-posterior diameter of the lateral talar domes included in this study was 45.1mm. An anterolateral approach to the ankle with arthrotomy provided a mean exposure of the anterior 1/3rd of the lateral talar dome. ATFL release increased this to 43.2%. A lateral malleolus osteotomy provided superior exposure (81.5% vs 58.8%) compared to an anterolateral tibial osteotomy. Only the anterior half of the lateral border of the talar dome could be accessed with an anterolateral approach without osteotomy. A fibular osteotomy provided best exposure to the posterolateral aspect of the talar dome and is recommended for lesions affecting the posterior half of the lateral talar dome

Aims

No randomized comparative study has compared the extensile lateral approach (ELA) and sinus tarsi approach (STA) for Sanders type 2 calcaneal fractures. This randomized comparative study was conducted to confirm whether the STA was prone to fewer wound complications than the ELA.

Aims

Malreduction of the syndesmosis has been reported in up to 52% of patients after fixation of ankle fractures. Multiple radiological parameters are used to define malreduction; there has been limited investigation of the accuracy of these measurements in differentiating malreduction from inherent anatomical asymmetry. The purpose of this study was to identify the prevalence of positive malreduction standards within the syndesmosis of native, uninjured ankles.

Title. 3D distribution of cortical bone thickness in the proximal humerus, implications for fracture management. Introduction. CT imaging is commonly used to gain a better understanding of proximal humerus fractures. the operating surgeon however has a limited capacity to evaluate the internal bone geometry from these clinical CT images. our aim was to use clinical CT in a novel way of accurately mapping cortical bone geometry in the proximal humerus. we planned to experimentally define the cortico-cancellous border in a cadaveric study and use CT imaging software to map out cortical thickness distribution in our specimens. Methodology. With ethical approval we used fifteen fresh frozen human proximal humeri. These were stripped of all soft tissue and transverse CT images taken with a GE VCT Lightspeed scanner. The humeral heads were then subsequently resected to allow access to the methaphyseal area. Using currettes, cancellous bone was removed down to hard cortical bone. Another set of CT images of the reamed specimen were then taken. Using Mimics imaging software[Materialise, Leuven] and a CAD interface, 3-matic [Materialise, Leuven], we built 3D model representations of our intact and reamed specimens. We first had to define an accurate CT density threshold for visualising cortical contours. We then analysed cortical thickness distribution based on that experimented threshold. Results. we were able to statistically determine the CT threshold, in Hounsfield Units, that represents the cortico-cancellous interface in the proximal humerus. Our 3D colour models provide an accurate depiction of the distribution of cortical thickness in the proximal humerus. Discussion/Conclusions. Our Hounsfield value for the cortico-cancellous interface in the proximal humerus agrees with a similar range of 400 to 800 HU reported in the literature for the proximal femur. Knowledge of regional variations in cortical bone thickness has direct implications for basic science studies on osteoporosis and its treatment, but is also important for the orthopaedic surgeon since our decision for treatment options is often guided by local bone quality

Objectives. Osteochondral ankle defects (OCDs) mainly occur in a young, active population. In 63% of cases the defect is located on the medial talar dome. Arthroscopic debridement and microfracture is considered the primary treatment for defects up to 15 mm. To treat patients with a secondary OCD of the medial talar dome, a 15-mm diameter metal implant (HemiCAP ®) was developed. The set of 15 offset sizes was designed to correspond with the anatomy of various talar dome curvatures. Recently, two independent biomechanical cadaver studies were published, providing rationale for clinical use. The present study was undertaken to evaluate the clinical effectiveness and safety of the metal implantation technique for osteochondral lesions of the medial talar dome in a prospective study. Material and methods. Since October 2007, twenty patients have been treated with the implant. Four patients who did not meet the inclusion criteria and four patients who had less than one-year follow-up at the time of writing were left out of this analysis. Twelve patients are reported with one year (n=8) or two years (n=4) follow-up. All patients had had one or two earlier operations without success. On preoperative CT-scanning, the mean lesion size was 16 × 11 (range, 9–26 × 8–14) mm. Outcome measures were: Numeric Rating Scale pain (NRS) at rest and when walking, Foot Ankle Outcome Score (FAOS), American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot score, and clinical and radiographic complications. Data are presented as median and range. The Wilcoxon signed ranks test was used to calculate p-values. Results. All patients recovered well from surgery. The NRS at rest improved from 3 (0–7) preoperatively, to 0.5 (0–4) after 1 year and 1 (0–1) after 2 years follow-up (p < 0.05). The NRS when walking was 6.5 (4–8) preoperatively, improving to 1.5 (0–5) at 1 year and 1 (0–2) at 2 years follow-up (p < 0.05). The five subscales of the FAOS improved from 14–64 preoperatively, to 53–91 after 1 year and 63–100 after 2 years (p < 0.05). The AOFAS improved from 70 (42–75) before surgery to 86 (58–100) at 1 year, and 89 (82–90) at 2 years follow-up (p < 0.05). There were no clinical or radiographic complications. Conclusion. The metallic implantation technique appears to be a promising treatment for secondary OCDs of the talus, but more patients and longer follow-up are necessary to draw firm conclusions

Introduction. Pedicle screw pullout or loosening is increased in the osteoporotic spine. Recent studies showed a significant increase of pullout forces especially for PMMA-augmentation. With application of conventional viscosity PMMA the risk of cement extravasation is associated. This risk can be reduced by using radiofrequency-responsive, ultrahigh viscosity bone cement. Method. 11 fresh-frozen lumbar vertebral bodies (VB) from 5 cadavers were collected and freed from soft-tissue and ligaments. By DEXA scan (Siemens QDR 2000) 8 VB were identified as severely osteoporotic (BMD 0.8 g/cm3), 3 VB were above this level. Two screws (6×45 mm, WSI-Expertise Inject, Peter Brehm, Weisendorf, Germany) were placed in the pedicles. Through the right screw 3ml of radiofrequency-responsive bone cement (StabiliT® ER2 Bone Cement, DFine, Germany) were injected via hydraulic cement delivery system (StabiliT® Vertebral Augmentation System, DFine, Germany). As control group, left pedicle screws remained uncemented. After potting the whole VB in technical PMMA (Technovit 4004, Heraeus Kulzer, Germany) axial pullout test was performed by a material testing device (Zwick-Roell, Zmart-Pro, Ulm, Germany). Results. The mean BMD of all specimen was 0.771 g/cm3 (min./max. 0.615/1.116, SD ± 0.170). Due to the definition of osteoporosis 8 specimens had a BMD lower than 0.8 g/cm3 (mean 0.677, min./max. 0.615/0,730, SD ±0.045). The non-osteoporotic group consisted of 3 specimens with a mean BMD of 1.020 g/cm3 (min/max 0.928/1.116, SD ±0.094). Overall we observed an increase in the mean axial pullout strength of 284% when using cement augmentated screws (non-cemented 385 N vs. cemented 1029 N, p 0,001). In the osteoporotic group the mean pullout force of the non-cemented screws was 407 N vs. 1022 N for the cemented screws (p 0.001). Similarly the pullout force rose in the non-osteoporotic group from 325 N for the non-cemented screws to 1048 N for the cemented screws p 0,001). All surgical procedures could be performed without technical problems. Conclusion. This cadaver study demonstrates the efficacy and effectiveness of pedicle-screw augmentation with ultra-high viscosity cement. Pullout forces are significantly increased, especially in osteoporotic bone. No complications like clogged in cannulated pedicle-screws or extravasation of bone cement were observed. In daily clinical routine radiation exposure to operator during cement delivery is reduced due to remote-controlled, automated delivery of radiofrequency-responsive bone cement. Furthermore availability of longer time to work with the cement (up to 30 min) is achieved; hectically injection or multiple-cement-mixing is not necessary anymore. The WSI-Expertise cannulated pedicle screws can be inserted and also augmented in a minimal-invasive technique. The PMMA then is injected through an extension adapter. PMMA augmentation of pedicle screws is already well established in spine surgery. With the combination of radiofrequency-responsive, ultra-high viscosity bone cement and cannulated pedicle screws this established procedure could become more controlled and safer for both patient and physician

Aim

There is not adequate evidence to establish whether external fixation (EF) of pelvic fractures leads to a reduced mortality. We used the Japan Trauma Data Bank database to identify isolated unstable pelvic ring fractures to exclude the possibility of blood loss from other injuries, and analyzed the effectiveness of EF on mortality in this group of patients.

Aims

The fundamental concept of open reduction and internal fixation (ORIF) of ankle fractures has not changed appreciably since the 1960s and, whilst widely used, is associated with complications including wound dehiscence and infection, prominent hardware and failure. Closed reduction and intramedullary fixation (CRIF) using a fibular nail, wires or screws is biomechanically stronger, requires minimal incisions, and has low-profile hardware. We hypothesised that fibular nailing in the elderly would have similar functional outcomes to standard fixation, with a reduced rate of wound and hardware problems.

We hypothesised that the anterior and posterior walls of the body of the first sacral vertebra could be visualised with two different angles of inlet view, owing to the conical shape of the sacrum. Six dry male cadavers with complete pelvic rings and eight dry sacrums with K-wires were used to study the effect of canting (angling the C-arm) the fluoroscope towards the head in 5° increments from 10° to 55°. Fluoroscopic images were taken in each position. Anterior and posterior angles of inclination were measured between the upper sacrum and the vertical line on the lateral view. Three authors separately selected the clearest image for overlapping anterior cortices and the upper sacral canal in the cadaveric models. The dry bone and K-wire models were scored by the authors, being sure to check whether the K-wire was in or out.

In the dry bone models the mean score of the relevant inlet position of the anterior or posterior inclination was 8.875 (standard deviation (sd) 0.35), compared with the inlet position of the opposite inclination of –5.75 (sd 4.59). We found that two different inlet views should be used separately to evaluate the borders of the body of the sacrum using anterior and posterior inclination angles of the sacrum, during placement of iliosacral screws.

Cite this article: Bone Joint J 2015;97-B:705–10.

It is becoming increasingly common for a patient to have ipsilateral hip and knee replacements. The inter-prosthetic (IP) distance, the distance between the tips of hip and knee prostheses, has been thought to be associated with an increased risk of IP fracture. Small gap distances are generally assumed to act as stress risers, although there is no real biomechanical evidence to support this.

The purpose of this study was to evaluate the influence of IP distance, cortical thickness and bone mineral density on the likelihood of an IP femoral fracture.

A total of 18 human femur specimens were randomised into three groups by bone density and cortical thickness. For each group, a defined IP distance of 35 mm, 80 mm or 160 mm was created by choosing the appropriate lengths of component. The maximum fracture strength was determined using a four-point bending test.

The fracture force of all three groups was similar (p = 0.498). There was a highly significant correlation between the cortical area and the fracture strength (r = 0.804, p <  0.001), whereas bone density showed no influence.

This study suggests that the IP distance has little influence on fracture strength in IP femoral fractures: the thickness of the cortex seems to be the decisive factor.

Cite this article: Bone Joint J 2014;96-B:1378–84.

Most fractures of the radial head are stable undisplaced or minimally displaced partial fractures without an associated fracture of the elbow or forearm or ligament injury, where stiffness following non-operative management is the primary concern. Displaced unstable fractures of the radial head are usually associated with other fractures or ligament injuries, and restoration of radiocapitellar contact by reconstruction or prosthetic replacement of the fractured head is necessary to prevent subluxation or dislocation of the elbow and forearm. In fractures with three or fewer fragments (two articular fragments and the neck) and little or no metaphyseal comminution, open reduction and internal fixation may give good results. However, fragmented unstable fractures of the radial head are prone to early failure of fixation and nonunion when fixed. Excision of the radial head is associated with good long-term results, but in patients with instability of the elbow or forearm, prosthetic replacement is preferred.

This review considers the characteristics of stable and unstable fractures of the radial head, as well as discussing the debatable aspects of management, in light of the current best evidence.

Cite this article: Bone Joint J 2013;95-B:151–9.

The purpose of this study was to describe the radiological characteristics of a previously unreported finding: posterior iliac offset at the sacroiliac joint and to assess its association with pelvic instability as measured by initial displacement and early implant loosening or failure. Radiographs from 42 consecutive patients with a mean age of 42 years (18 to 77; 38 men, four women) and mean follow-up of 38 months (3 to 96) with Anteroposterior Compression II injuries, were retrospectively reviewed. Standardised measurements were recorded for the extent of any diastasis of the pubic symphysis, widening of the sacroiliac joint, static vertical ramus offset and a novel measurement (posterior offset of the ilium at the sacroiliac joint identified on axial CT scan). Pelvic fractures with posterior iliac offset exhibited greater levels of initial displacement of the anterior pelvis (anterior sacroiliac widening, pubic symphysis diastasis and static vertical ramus offset, p < 0.001,0.034 and 0.028, respectively). Pelvic fractures with posterior ilium offset also demonstrated higher rates of implant loosening regardless of fixation method (p = 0.05). Posterior offset of the ilium was found to be a reliable and reproducible measurement with substantial inter-observer agreement (kappa = 0.70). Posterior offset of the ilium on axial CT scan is associated with greater levels of initial pelvic displacement and early implant loosening.

Cite this article: Bone Joint J 2014;96-B:1535–9.

Coronal plane fractures of the posterior femoral condyle, also known as Hoffa fractures, are rare. Lateral fractures are three times more common than medial fractures, although the reason for this is not clear. The exact mechanism of injury is likely to be a vertical shear force on the posterior femoral condyle with varying degrees of knee flexion. These fractures are commonly associated with high-energy trauma and are a diagnostic and surgical challenge. Hoffa fractures are often associated with inter- or supracondylar distal femoral fractures and CT scans are useful in delineating the coronal shear component, which can easily be missed. There are few recommendations in the literature regarding the surgical approach and methods of fixation that may be used for this injury. Non-operative treatment has been associated with poor outcomes. The goals of treatment are anatomical reduction of the articular surface with rigid, stable fixation to allow early mobilisation in order to restore function. A surgical approach that allows access to the posterior aspect of the femoral condyle is described and the use of postero-anterior lag screws with or without an additional buttress plate for fixation of these difficult fractures.

Cite this article: Bone Joint J 2013;95-B:1165–71.

A delay in establishing the diagnosis of an occult fracture of the hip that remains unrecognised after plain radiography can result in more complex treatment such as an arthroplasty being required. This might be avoided by earlier diagnosis using MRI. The aim of this study was to investigate the best MR imaging sequence for diagnosing such fractures. From a consecutive cohort of 771 patients admitted between 2003 and 2011 with a clinically suspected fracture of the hip, we retrospectively reviewed the MRI scans of the 35 patients who had no evidence of a fracture on their plain radiographs. In eight of these patients MR scanning excluded a fracture but the remaining 27 patients had an abnormal scan: one with a fracture of the pubic ramus, and in the other 26 a T₁-weighted coronal MRI showed a hip fracture with 100% sensitivity. T₂-weighted imaging was undertaken in 25 patients, in whom the diagnosis could not be established with this scanning sequence alone, giving a sensitivity of 84.0% for T₂-weighted imaging.

If there is a clinical suspicion of a hip fracture with normal radiographs, T₁-weighted coronal MRI is the best sequence of images for identifying a fracture.

A new anterior intrapelvic approach for the surgical management of displaced acetabular fractures involving predominantly the anterior column and the quadrilateral plate is described. In order to establish five ‘windows’ for instrumentation, the extraperitoneal space is entered along the lateral border of the rectus abdominis muscle. This is the so-called ‘Pararectus’ approach. The feasibility of safe dissection and optimal instrumentation of the pelvis was assessed in five cadavers (ten hemipelves) before implementation in a series of 20 patients with a mean age of 59 years (17 to 90), of whom 17 were male. The clinical evaluation was undertaken between December 2009 and December 2010. The quality of reduction was assessed with post-operative CT scans and the occurrence of intra-operative complications was noted. In cadavers, sufficient extraperitoneal access and safe instrumentation of the pelvis were accomplished. In the patients, there was a statistically significant improvement in the reduction of the fracture (pre- versus post-operative: mean step-off 3.3 mm (sd 2.6) vs 0.1 mm (sd 0.3), p < 0.001; and mean gap 11.5 mm (sd 6.5) vs 0.8 mm (sd 1.3), p < 0.001). Lesions to the peritoneum were noted in two patients and minor vascular damage was noted in a further two patients. Multi-directional screw placement and various plate configurations were feasible in cadavers without significant retraction of soft tissues.

In the treatment of acetabular fractures predominantly involving the anterior column and the quadrilateral plate, the Pararectus approach allowed anatomical restoration with minimal morbidity related to the surgical access.

We randomly allocated 60 consecutive patients with fractures of the waist of the scaphoid to percutaneous fixation with a cannulated Acutrak screw or immobilisation in a cast. The range of movement, the grip and pinch strength, the modified Green/O’Brien functional score, return to work and sports, and radiological evidence of union were evaluated at each follow-up visit. Patients were followed sequentially for one year.

Those undergoing percutaneous screw fixation showed a quicker time to union (9.2 weeks vs 13.9 weeks, p < 0.001) than those treated with a cast. There was a trend towards a higher rate of nonunion in the non-operative group, although this was not statistically significant. Patients treated by operation had a more rapid return of function and to sport and full work compared with those managed conservatively. There was a very low complication rate.

We recommend that all active patients should be offered percutaneous stabilisation for fractures of the waist of the scaphoid.