In a retrospective cohort study we compared the clinical outcome and complications, including dysphagia, following anterior cervical fusion for the treatment of cervical spondylosis using either a zero-profile (Zero-P; Synthes) implant or an anterior cervical plate and cage. A total of 83 patients underwent fusion using a Zero-P and 107 patients underwent fusion using a plate and cage. The mean follow-up was 18.6 months (sd 4.2) in the Zero-P group and 19.3 months (sd 4.1) in the plate and cage group. All patients in both groups had significant symptomatic and neurological improvement. There were no significant differences between the groups in the Neck Disability Index (NDI) and visual analogue scores at final follow-up. The cervical alignment improved in both groups. There was a higher incidence of dysphagia in the plate and cage group on the day after surgery and at two months post-operatively. All patients achieved fusion and no graft migration or nonunion was observed.

When compared with the traditional anterior cervical plate and cage, the Zero-P implant is a safe and convenient procedure giving good results in patients with symptomatic cervical spondylosis with a reduced incidence of dysphagia post-operatively.

Cite this article: Bone Joint J 2013;95-B:543–7.

We determined the short-term clinical outcome and migration within the bone of the humeral cementless component of the Instrumented Bone Preserving (IBP) total elbow replacement in a series of 16 patients. There were four men and 12 women with a mean age at operation of 63 years (40 to 81). Migration was calculated using radiostereometric analysis. There were no intra-operative complications and no revisions. At two-year follow-up, all patients showed a significant reduction in pain and functional improvement of the elbow (both p < 0.001). Although ten components (63%) showed movement or micromovement during the first six weeks, 14 (88%) were stable at one year post-operatively. Translation was primarily found in the proximal direction (median 0.3 mm (interquartile range (IQR) -0.09 to 0.8); the major rotational movement was an anterior tilt (median 0.7° (IQR 0.4° to 1.6°)). One malaligned component continued to migrate during the second year, and one component could not be followed beyond three months because migration had caused the markers to break off the prosthesis.

This study shows promising early results for the cementless humeral component of the IBP total elbow replacement. All patients had a good clinical outcome, and most components stabilised within six months of the operation.

Cite this article: Bone Joint J 2014;96-B:229–36.

We retrospectively reviewed the records of 1150 computer-assisted total knee replacements and analysed the clinical and radiological outcomes of 45 knees that had arthritis with a pre-operative recurvatum deformity. The mean pre-operative hyperextension deformity of 11° (6° to 15°), as measured by navigation at the start of the operation, improved to a mean flexion deformity of 3.1° (0° to 7°) post-operatively. A total of 41 knees (91%) were managed using inserts ≤ 12.5 mm thick, and none had mediolateral laxity > 2 mm from a mechanical axis of 0° at the end of the surgery. At a mean follow-up of 26.4 months (13 to 48) there was significant improvement in the mean Knee Society, Oxford knee and Western Ontario and McMaster Universities Osteoarthritis Index scores compared with the pre-operative values. The mean knee flexion improved from 105° (80° to 125°) pre-operatively to 131° (120° to 145°), and none of the limbs had recurrent recurvatum.

These early results show that total knee replacement using computer navigation and an algorithmic approach for arthritic knees with a recurvatum deformity can give excellent radiological and functional outcomes without recurrent deformity.

The December 2014 Foot & Ankle Roundup360 looks at: Charcot feet, biomarkers and diabetes; weight bearing following Achilles tendon rupture; endobuttons and mal-reduced diastasis; evidence for stem cell therapies in osteochondral lesions of the talus; syndesmosis fixation in SER ankle fractures; and self-reporting for foot and ankle outcomes.

In this in vitro study of the hip joint we examined which soft tissues act as primary and secondary passive rotational restraints when the hip joint is functionally loaded. A total of nine cadaveric left hips were mounted in a testing rig that allowed the application of forces, torques and rotations in all six degrees of freedom. The hip was rotated throughout a complete range of movement (ROM) and the contributions of the iliofemoral (medial and lateral arms), pubofemoral and ischiofemoral ligaments and the ligamentum teres to rotational restraint was determined by resecting a ligament and measuring the reduced torque required to achieve the same angular position as before resection. The contribution from the acetabular labrum was also measured. Each of the capsular ligaments acted as the primary hip rotation restraint somewhere within the complete ROM, and the ligamentum teres acted as a secondary restraint in high flexion, adduction and external rotation. The iliofemoral lateral arm and the ischiofemoral ligaments were primary restraints in two-thirds of the positions tested. Appreciation of the importance of these structures in preventing excessive hip rotation and subsequent impingement/instability may be relevant for surgeons undertaking both hip joint preserving surgery and hip arthroplasty.

Cite this article: Bone Joint J 2015; 97-B:484–91.

Stems may improve fixation and stability of components during revision total knee replacement. However, the choice between cemented and cementless stems is not a clear one. Cemented stems offer several advantages in terms of versatility, mechanical stability, surgical technique and clinical outcome over their cementless counterpart.

Cite this article: Bone Joint J 2014;96-B(11 Suppl A):115–7.

We studied the intra- and interobserver reliability of measurements of the position of the components after total knee replacement (TKR) using a combination of radiographs and axial two-dimensional (2D) and three-dimensional (3D) reconstructed CT images to identify which method is best for this purpose.

A total of 30 knees after primary TKR were assessed by two independent observers (an orthopaedic surgeon and a radiologist) using radiographs and CT scans. Plain radiographs were highly reliable at measuring the tibial slope, but showed wide variability for all other measurements; 2D-CT also showed wide variability. 3D-CT was highly reliable, even when measuring rotation of the femoral components, and significantly better than 2D-CT. Interobserver variability in the measurements on radiographs were good (intraclass correlation coefficient (ICC) 0.65 to 0.82), but rotational measurements on 2D-CT were poor (ICC 0.29). On 3D-CT they were near perfect (ICC 0.89 to 0.99), and significantly more reliable than 2D-CT (p < 0.001).

3D-reconstructed images are sufficiently reliable to enable reporting of the position and orientation of the components. Rotational measurements in particular should be performed on 3D-reconstructed CT images. When faced with a poorly functioning TKR with concerns over component positioning, we recommend 3D-CT as the investigation of choice.

We investigated the stability of seven Schatzker type II fractures of the lateral tibial plateau treated by subchondral screws and a buttress plate followed by immediate partial weight-bearing. In order to assess the stability of the fracture, weight-bearing inducible displacements of the fracture fragments and their migration over a one-year period were measured by differentially loaded radiostereometric analysis and standard radiostereometric analysis, respectively. The mean inducible craniocaudal fracture fragment displacements measured −0.30 mm (−0.73 to 0.02) at two weeks and 0.00 mm (−0.12 to 0.15) at 52 weeks. All inducible displacements were elastic in nature under all loads at each examination during follow-up. At one year, the mean craniocaudal migration of the fracture fragments was −0.34 mm (−1.64 to 1.51).

Using radiostereometric methods, this case series has shown that in the Schatzker type II fractures investigated, internal fixation with subchondral screws and a buttress plate provided adequate stability to allow immediate post-operative partial weight-bearing, without harmful consequences.

Although gradual bone transport may permit the restoration of large-diameter bones, complications are common owing to the long duration of external fixation. In order to reduce such complications, a new technique of bone transport involving the use of an external fixator and a locking plate was devised for segmental tibial bone defects.

A total of ten patients (nine men, one woman) with a mean age at operation of 40.4 years (16 to 64) underwent distraction osteogenesis with a locking plate to treat previously infected post-traumatic segmental tibial defects. The locking plate was fixed percutaneously to bridge proximal and distal segments, and was followed by external fixation. After docking, percutaneous screws were fixed at the transported segment through plate holes. At the same time, bone grafting was performed at the docking site with the external fixator removed.

The mean defect size was 5.9 cm (3.8 to 9.3) and mean external fixation index was 13.4 days/cm (11.8 to 19.5). In all cases, primary union of the docking site and distraction callus was achieved, with an excellent bony result. There was no recurrence of deep infection or osteomyelitis, and with the exception of one patient with a pre-existing peroneal nerve injury, all achieved an excellent or good functional result.

With short external fixation times and low complication rates, bone transport with a locking plate could be recommended for patients with segmental tibial defects.

Cite this article: Bone Joint J 2013;95-B:1667–72.

The identification of the extent of neural damage in patients with acute or chronic spinal cord injury is imperative for the accurate prediction of neurological recovery. The changes in signal intensity shown on routine MRI sequences are of limited value for predicting functional outcome. Diffusion tensor imaging (DTI) is a novel radiological imaging technique which has the potential to identify intact nerve fibre tracts, and has been used to image the brain for a variety of conditions. DTI imaging of the spinal cord is currently only a research tool, but preliminary studies have shown that it holds considerable promise in predicting the severity of spinal cord injury.

This paper briefly reviews our current knowledge of this technique.

We investigated the incidence and risk factors for the development of avascular necrosis (AVN) of the femoral head in the course of treatment of children with cerebral palsy (CP) and dislocation of the hip. All underwent open reduction, proximal femoral and Dega pelvic osteotomy. The inclusion criteria were: a predominantly spastic form of CP, dislocation of the hip (migration percentage, MP > 80%), Gross Motor Function Classification System, (GMFCS) grade IV to V, a primary surgical procedure and follow-up of > one year.

There were 81 consecutive children (40 girls and 41 boys) in the study. Their mean age was nine years (3.5 to 13.8) and mean follow-up was 5.5 years (1.6 to 15.1). Radiological evaluation included measurement of the MP, the acetabular index (AI), the epiphyseal shaft angle (ESA) and the pelvic femoral angle (PFA). The presence and grade of AVN were assessed radiologically according to the Kruczynski classification.

Signs of AVN (grades I to V) were seen in 79 hips (68.7%). A total of 23 hips (18%) were classified between grades III and V.

Although open reduction of the hip combined with femoral and Dega osteotomy is an effective form of treatment for children with CP and dislocation of the hip, there were signs of avascular necrosis in about two-thirds of the children. There was a strong correlation between post-operative pain and the severity of the grade of AVN.

Cite this article: Bone Joint J 2015;97-B:270–6.

We report five children who presented at the mean age of 1.5 years (1.1 to 1.9) with a progressive thoracolumbar kyphosis associated with segmental instability and subluxation of the spine at the level above an anteriorly-wedged hypoplastic vertebra at L1 or L2. The spinal deformity appeared to be developmental and not congenital in origin. The anterior wedging of the vertebra may have been secondary to localised segmental instability and subsequent kyphotic deformity.

We suggest the term ‘infantile developmental thoracolumbar kyphosis with segmental subluxation of the spine’ to differentiate this type of deformity from congenital displacement of the spine in which the congenital vertebral anomaly does not resolve. Infantile developmental kyphosis with segmental subluxation of the spine, if progressive, may carry the risk of neurological compromise. In all of our patients the kyphotic deformity progressed over a period of three months and all were treated by localised posterior spinal fusion. At a mean follow-up of 6.6 years (5.0 to 9.0), gradual correction of the kyphosis was seen on serial radiographs as well as reconstitution of the hypoplastic wedged vertebra to normality. Exploration of the arthrodesis was necessary at nine months in one patient who developed a pseudarthrosis.

Progressive degenerative changes in the medial compartment of the knee following lateral unicompartmental arthroplasty (UKA) remains a leading indication for revision surgery. The purpose of this study is to evaluate changes in the congruence and joint space width (JSW) of the medial compartment following lateral UKA. The congruence of the medial compartment of 53 knees (24 men, 23 women, mean age 13.1 years; sd 62.1) following lateral UKA was evaluated pre-operatively and six weeks post-operatively, and compared with 41 normal knees (26 men, 15 women, mean age 33.7 years; sd 6.4), using an Interactive closest point algorithm which calculated the congruence index (CI) by performing a rigid transformation that best aligns the digitised tibial and femoral surfaces. Inner, middle and outer JSWs were measured by sub-dividing the medial compartment into four quarters on pre- and post-operative, weight bearing tunnel view radiographs. The mean CI of knees following lateral UKA significantly improved from 0.92 (sd 0.06) pre-operatively to 0.96 (sd 0.02) (p < 0.001) six weeks post-operatively. The mean CI of the healthy control group was 0.99 sd 0.01. Post-operatively, the mean inner JSW increased (p = 0.006) and the outer decreased (p = 0.002). The JSW was restored post-operatively as no significant differences were noted in all three locations compared with the control group (inner JSW p = 0.43; middle JSW p = 0.019, outer JSW p = 0.51).

Our data suggest that a well conducted lateral UKA may improve the congruence and normalise the JSW of the medial compartment, potentially preventing progression of degenerative change.

Cite this article: Bone Joint J 2015;97-B:50–5.

We continued a prospective longitudinal follow-up study of 53 remaining patients who underwent open total meniscectomy as adolescents and who at that time had no other intra-articular pathology of the knee. Their clinical, radiological and patient-reported outcomes are described at a mean follow-up of 40 years (33 to 50). The cohort of patients who had undergone radiological evaluation previously after 30 years were invited for clinical examination, radiological evaluation and review using two patient-reported outcome measures.

A total of seven patients (13.2%) had already undergone total knee replacement at the time of follow-up. A significant difference was observed between the operated and non-operated knee in terms of range of movement and osteoarthritis of the tibiofemoral joint, indicating a greater than fourfold relative risk of osteoarthritis at 40 years post-operatively. All patients were symptomatic as defined by the Knee Injury and Osteoarthritis Outcome Score.

This study represents the longest follow-up to date and it can be concluded that meniscectomy leads to symptomatic osteoarthritis of the knee later in life, with a resultant 132-fold increase in the rate of total knee replacement in comparison to their geographical and age-matched peers.

We studied the prevalence of severe crouch gait over a 15-year period in a defined population of children with spastic diplegia and Gross Motor Function Classification System levels II and III, to determine if there had been a decrease following changes to the management of equinus gait. These changes were replacing observational with three-dimensional gait analysis, replacing single level with multilevel surgery, and replacing gastrocsoleus lengthening with gastrocnemius recession. Of 464 children and adolescents with spastic diplegia who underwent three-dimensional gait analysis, 27 had severe crouch gait. Seventeen of these had been managed by isolated lengthening of the gastrocsoleus. Following changes in the management of equinus gait, the prevalence of severe crouch gait decreased from 25% and stabilised at a significantly lower rate, fluctuating between 0% and 4% annually (p < 0.001).

We conclude that severe crouch gait in this population was precipitated by isolated lengthening of the gastrocsoleus. These findings may be relevant to other surgical populations, as severe crouch gait may be a useful way to monitor the quality of the surgical management of abnormal gait in children with cerebral palsy and spastic diplegia.

A review of the current literature shows that there is a lack of consensus regarding the treatment of spondylolysis and spondylolisthesis in children and adolescents. Most of the views and recommendations provided in various reports are weakly supported by evidence. There is a limited amount of information about the natural history of the condition, making it difficult to compare the effectiveness of various conservative and operative treatments. This systematic review summarises the current knowledge on spondylolysis and spondylolisthesis and attempts to present a rational approach to the evaluation and management of this condition in children and adolescents.

Progressive angular deformity of an extremity due to differential physeal arrest is the most common late orthopaedic sequela following meningococcal septicaemia in childhood. A total of ten patients (14 ankles) with distal tibial physeal arrest as a consequence of meningococcal septicaemia have been reviewed. Radiological analysis of their ankles has demonstrated a distinct pattern of deformity. In 13 of 14 cases the distal fibular physis was unaffected and continued distal fibular growth contributed to a varus deformity. We recommend that surgical management should take account of this consistent finding during the correction of these deformities.

Previous studies of failure mechanisms leading to revision total knee replacement (TKR) performed between 1986 and 2000 determined that many failed early, with a disproportionate amount accounted for by infection and implant-associated factors including wear, loosening and instability. Since then, efforts have been made to improve implant performance and instruct surgeons in best practice. Recently our centre participated in a multi-centre evaluation of 844 revision TKRs from 2010 to 2011. The purpose was to report a detailed analysis of failure mechanisms over time and to see if failure modes have changed over the past 10 to 15 years. Aseptic loosening was the predominant mechanism of failure (31.2%), followed by instability (18.7%), infection (16.2%), polyethylene wear (10.0%), arthrofibrosis (6.9%) and malalignment (6.6%). The mean time to failure was 5.9 years (ten days to 31 years), 35.3% of all revisions occurred at less than two years, and 60.2% in the first five years. With improvements in implant and polyethylene manufacture, polyethylene wear is no longer a leading cause of failure. Early mechanisms of failure are primarily technical errors. In addition to improving implant longevity, industry and surgeons must work together to decrease these technical errors. All reports on failure of TKR contain patients with unexplained pain who not infrequently have unmet expectations. Surgeons must work to achieve realistic patient expectations pre-operatively, and therefore, improve patient satisfaction post-operatively.

Cite this article: Bone Joint J 2014;96-B(11 Suppl A):101–4.

Cancellous allograft bone chips are commonly used in the reconstruction of defects in bone after removal of benign tumours. We investigated the MRI features of grafted bone chips and their change over time, and compared them with those with recurrent tumour. We retrospectively reviewed 66 post-operative MRIs from 34 patients who had undergone curettage and grafting with cancellous bone chips to fill the defect after excision of a tumour. All grafts showed consistent features at least six months after grafting: homogeneous intermediate or low signal intensities with or without scattered hyperintense foci (speckled hyperintensities) on T1 images; high signal intensities with scattered hypointense foci (speckled hypointensities) on T2 images, and peripheral rim enhancement with or without central heterogeneous enhancements on enhanced images. Incorporation of the graft occurred from the periphery to the centre, and was completed within three years. Recurrent lesions consistently showed the same signal intensities as those of pre-operative MRIs of the primary lesions. There were four misdiagnoses, three of which were chondroid tumours.

We identified typical MRI features and clarified the incorporation process of grafted cancellous allograft bone chips. The most important characteristics of recurrent tumours were that they showed the same signal intensities as the primary tumours. It might sometimes be difficult to differentiate grafted cancellous allograft bone chips from a recurrent chondroid tumour.

Cite this article: Bone Joint J 2015;97-B:121–8.

A displaced fracture of the scaphoid is one in which the fragments have moved from their anatomical position or there is movement between them when stressed by physiological loads. Displacement is seen in about 20% of fractures of the waist of the scaphoid, as shown by translation, a gap, angulation or rotation. A CT scan in the true longitudinal axis of the scaphoid demonstrates the shape of the bone and displacement of the fracture more accurately than do plain radiographs. Displaced fractures can be treated in a plaster cast, accepting the risk of malunion and nonunion. Surgically the displacement can be reduced, checked radiologically, arthroscopically or visually, and stabilised with headless screws or wires. However, rates of union and deformity are unknown. Mild malunion is well tolerated, but the long-term outcome of a displaced fracture that healed in malalignment has not been established.

This paper summarises aspects of the assessment, treatment and outcome of displaced fractures of the waist of the scaphoid.