Many aspects of total knee arthroplasty have changed since its inception. Modern prosthetic design, better fixation techniques, improved polyethylene wear characteristics and rehabilitation, have all contributed to a large change in revision rates. Arthroplasty patients now expect longevity of their prostheses and demand functional improvement to match. This has led to a re-examination of the long-held belief that mechanical alignment is instrumental to a successful outcome and a focus on restoring healthy joint kinematics. A combination of kinematic restoration and uncemented, adaptable fixation may hold the key to future advances.

Cite this article: Bone Joint J 2015;97-B(10 Suppl A):16–19.

Aims

Oxidised zirconium was introduced as a material for femoral components in total knee arthroplasty (TKA) as an attempt to reduce polyethylene wear. However, the long-term survival of this component is not known.

Arthroscopy has become a routine surgical procedure, used as a diagnostic and therapeutic tool for the treatment of joint problems. This article discusses its origins and looks at how it is currently used.

Percutaneous placement of pedicle screws is a well-established technique, however, no studies have compared percutaneous and open placement of screws in the thoracic spine. The aim of this cadaveric study was to compare the accuracy and safety of these techniques at the thoracic spinal level. A total of 288 screws were inserted in 16 (eight cadavers, 144 screws in percutaneous and eight cadavers, 144 screws in open). Pedicle perforations and fractures were documented subsequent to wide laminectomy followed by skeletalisation of the vertebrae. The perforations were classified as grade 0: no perforation, grade 1: < 2 mm perforation, grade 2: 2 mm to 4 mm perforation and grade 3: > 4 mm perforation. In the percutaneous group, the perforation rate was 11.1% with 15 (10.4%) grade 1 and one (0.7%) grade 2 perforations. In the open group, the perforation rate was 8.3% (12 screws) and all were grade 1. This difference was not significant (p = 0.45). There were 19 (13.2%) pedicle fractures in the percutaneous group and 21 (14.6%) in the open group (p = 0.73). In summary, the safety of percutaneous fluoroscopy-guided pedicle screw placement in the thoracic spine between T4 and T12 is similar to that of the conventional open technique.

Cite this article: Bone Joint J 2015;97-B:1555–61.

Mechanical alignment has been a fundamental tenet of total knee arthroplasty (TKA) since modern knee replacement surgery was developed in the 1970s. The objective of mechanical alignment was to infer the greatest biomechanical advantage to the implant to prevent early loosening and failure. Over the last 40 years a great deal of innovation in TKA technology has been focusing on how to more accurately achieve mechanical alignment. Recently the concept of mechanical alignment has been challenged, and other alignment philosophies are being explored with the intention of trying to improve patient outcomes following TKA.

This article examines the evolution of the mechanical alignment concept and whether there are any viable alternatives.

Cardiac disease in patients with ankylosing spondylitis (AS) has previously been studied but not in patients with a kyphosis or in those who have undergone an operation to correct it.

The aim of this study was to measure the post-operative changes in cardiac function of patients with an AS kyphosis after pedicle subtraction osteotomy (PSO).

The original cohort consisted of 39 patients (33 men, six women). Of these, four patients (two men, two women) were lost to follow-up leaving 35 patients (31 men, four women) to study. The mean age of the remaining patients was 37.4 years (22.3 to 47.8) and their mean duration of AS was 17.0 years (4.6 to 26.4). Echocardiographic measurements, resting heart rate (RHR), physical function score (PFS), and full-length standing spinal radiographs were obtained before surgery and at the two-year follow-up.

The mean pre-operative RHR was 80.2 bpm (60.6 to 112.3) which dropped to a mean of 73.7 bpm (60.7 to 90.6) at the two-year follow-up (p = 0.0000). Of 15 patients with normal ventricular function pre-operatively, two developed mild left ventricular diastolic dysfunction (LVDD) at the two-year follow-up. Of 20 patients with mild LVDD pre-operatively only five had this post-operatively. Overall, 15 patients had normal LV diastolic function before their operation and 28 patients had normal LV function at the two-year follow-up.

The clinical improvement was 15 out of 20 (75.0%): cardiac function in patients with AS whose kyphosis was treated by PSO was significantly improved.

Cite this article: Bone Joint J 2015;97-B:1405–10.

C5 nerve root palsy is a rare and potentially debilitating complication of cervical spine surgery. Currently, however, there are no guidelines to help surgeons to prevent or treat this complication.

We carried out a systematic review of the literature to identify the causes of this complication and options for its prevention and treatment. Searches of PubMed, Embase and Medline yielded 60 articles for inclusion, most of which addressed C5 palsy as a complication of surgery. Although many possible causes were given, most authors supported posterior migration of the spinal cord with tethering of the nerve root as being the most likely.

Early detection and prevention of a C5 nerve root palsy using neurophysiological monitoring and variations in surgical technique show promise by allowing surgeons to minimise or prevent the incidence of C5 palsy. Conservative treatment is the current treatment of choice; most patients make a full recovery within two years.

Cite this article: Bone Joint J 2014;96-B:950–5.

A total of 22 patients with a tibial avulsion fracture involving the insertion of the posterior cruciate ligament (PCL) with grade II or III posterior laxity were reduced and fixed arthroscopically using routine anterior and double posteromedial portals. A double-strand Ethibond suture was inserted into the joint and wrapped around the PCL from anterior to posterior to secure the ligament above the avulsed bony fragment. Two tibial bone tunnels were created using the PCL reconstruction guide, aiming at the medial and lateral borders of the tibial bed. The ends of the suture were pulled out through the bone tunnels and tied over the tibial cortex between the openings of the tunnels to reduce and secure the bony fragment. Satisfactory reduction of the fracture was checked arthroscopically and radiographically.

The patients were followed-up for a mean of 24.5 months (19 to 28). Bone union occurred six weeks post-operatively. At final follow-up, all patients had a negative posterior drawer test and a full range of movement. KT-1000 arthrometer examination showed that the mean post-operative side-to-side difference improved from 10.9 mm (standard deviation (sd) 0.7) pre-operatively to 1.5 mm (sd 0.6) (p = 0.001). The mean Tegner and the International Knee Documentation Committee scores improved significantly (p = 0.001). The mean Lysholm score at final follow-up was 92.0 (85 to 96).

We conclude that this technique is convenient, reliable and minimally invasive and successfully restores the stability and function of the knee.

Cite this article: Bone Joint J 2015;97-B:1220–5.

The April 2014 Spine Roundup³⁶⁰ looks at: medical treatment for ankylosing spondylitis; unilateral TLIF effective; peg fractures akin to neck of femur fractures; sleep apnoea and spinal surgery; scoliosis in osteogenesis imperfect; paediatric atlanto-occipital dislocation; back pain and obesity: chicken or egg?; BMP associated with lumbar plexus deficit; and just how common is back pain?

In England and Wales more than 175 000 hip and knee arthroplasties were performed in 2012. There continues to be a steady increase in the demand for joint arthroplasty because of population demographics and improving survivorship. Inevitably though the absolute number of periprosthetic infections will probably increase with severe consequences on healthcare provision. The Department of Health and the Health Protection Agency in United Kingdom established a Surgical Site Infection surveillance service (SSISS) in 1997 to undertake surveillance of surgical site infections. In 2004 mandatory reporting was introduced for one quarter of each year. There has been a wide variation in reporting rates with variable engagement with the process. The aim of this article is to improve surgeon awareness of the process and emphasise the importance of engaging with SSISS to improve the quality and type of data submitted. In Exeter we have been improving our practice by engaging with SSISS. Orthopaedic surgeons need to take ownership of the data that are submitted to ensure these are accurate and comprehensive.

Cite this article: Bone Joint J 2015;97-B:1170–4.

The purpose of this study was to evaluate the long-term outcome of adults with spina bifida cystica (SBC) who had been treated either operatively or non-operatively for scoliosis during childhood.

We reviewed 45 patients with a SBC scoliosis (Cobb angle ≥ 50º) who had been treated at one of two children’s hospitals between 1991 and 2007. Of these, 34 (75.6%) had been treated operatively and 11 (24.4%) non-operatively. After a mean follow-up of 14.1 years (standard deviation (sd) 4.3) clinical, radiological and health-related quality of life (HRQOL) outcomes were evaluated using the Spina Bifida Spine Questionnaire (SBSQ) and the 36-Item Short Form Health Survey (SF-36).

Although patients in the two groups were demographically similar, those who had undergone surgery had a larger mean Cobb angle (88.0º (sd 20.5; 50.0 to 122.0); versus 65.7º (sd 22.0; 51.0 to 115.0); p < 0.01) and a larger mean clavicle–rib intersection difference (12.3 mm; (sd 8.5; 1 to 37); versus 4.1 mm, (sd 5.9; 0 to 16); p = 0.01) than those treated non-operatively. Both groups were statistically similar at follow-up with respect to walking capacity, neurological motor level, sitting balance and health-related quality of life (HRQOL) outcomes.

Spinal fusion in SBC scoliosis corrects coronal deformity and stops progression of the curve but has no clear effect on HRQOL.

Cite this article: Bone Joint J 2014; 96-B:1244–51

The February 2014 Spine Roundup³⁶⁰ looks at: single posterior approach for severe kyphosis; risk factors for recurrent disc herniation; dysphagia and cervical disc replacement or fusion; hang on to your topical antibiotics; cost-effective lumbar disc replacement; anxiolytics no role to play in acute lumbar back pain; and surgery best for lumbar disc herniation.

Partial knee arthroplasty (PKA), either medial or lateral unicompartmental knee artroplasty (UKA) or patellofemoral arthroplasty (PFA) are a good option in suitable patients and have the advantages of reduced operative trauma, preservation of both cruciate ligaments and bone stock, and restoration of normal kinematics within the knee joint. However, questions remain concerning long-term survival. The goal of this review article was to present the long-term results of medial and lateral UKA, PFA and combined compartmental arthroplasty for multicompartmental disease. Medium- and long-term studies suggest reasonable outcomes at ten years with survival greater than 95% in UKA performed for medial osteoarthritis or osteonecrosis, and similarly for lateral UKA, particularly when fixed-bearing implants are used. Disappointing long-term outcomes have been observed with the first generation of patellofemoral implants, as well as early Bi-Uni (ie, combined medial and lateral UKA) or Bicompartmental (combined UKA and PFA) implants due to design and fixation issues. Promising short- and med-term results with the newer generations of PFAs and bicompartmental arthroplasties will require long-term confirmation.

Cite this article: Bone Joint J 2015;97-B(10 Suppl A):9–15.

This prospective study reports the 15-year survival and ten-year functional outcome of a consecutive series of 1000 minimally invasive Phase 3 Oxford medial UKAs (818 patients, 393 men, 48%, 425 women, 52%, mean age 66 years; 32 to 88). These were implanted by two surgeons involved with the design of the prosthesis to treat anteromedial osteoarthritis and spontaneous osteonecrosis of the knee, which are recommended indications. Patients were prospectively identified and followed up independently for a mean of 10.3 years (5.3 to 16.6).

At ten years, the mean Oxford Knee Score was 40 (standard deviation (sd) 9; 2 to 48): 79% of knees (349) had an excellent or good outcome. There were 52 implant-related re-operations at a mean of 5.5 years (0.2 to 14.7). The most common reasons for re-operation were arthritis in the lateral compartment (2.5%, 25 knees), bearing dislocation (0.7%, seven knees) and unexplained pain (0.7%, seven knees). When all implant-related re-operations were considered as failures, the ten-year rate of survival was 94% (95% confidence interval (CI) 92 to 96) and the 15-year survival rate 91% (CI 83 to 98). When failure of the implant was the endpoint the 15-year survival was 99% (CI 96 to 100).

This is the only large series of minimally invasive UKAs with 15-year survival data. The results support the continued use of minimally invasive UKA for the recommended indications.

Cite this article: Bone Joint J 2015;97-B:1493–99.

Acute angulation at the thoracolumbar junction with segmental subluxation of the spine occurring at the level above an anteriorly hypoplastic vertebra in otherwise normal children is a rare condition described as infantile developmental thoracolumbar kyphosis. Three patient series with total of 18 children have been reported in the literature. We report five children who presented with thoracolumbar kyphosis and discuss the treatment algorithm. We reviewed the medical records and spinal imaging at initial clinical presentation and at minimum two-year follow-up. The mean age at presentation was eight months (two to 12). All five children had L2 anterior vertebral body hypoplasia. The kyphosis improved spontaneously in three children kept under monitoring. In contrast, the deformity was progressive in two patients who were treated with bracing. The kyphosis and segmental subluxation corrected at latest follow-up (mean age 52 months; 48 to 60) in all patients with near complete reconstitution of the anomalous vertebra. The deformity and radiological imaging on a young child can cause anxiety to both parents and treating physicians. Diagnostic workup and treatment algorithm in the management of infantile developmental thoracolumbar kyphosis is proposed. Observation is indicated for non-progressive kyphosis and bracing if there is evidence of kyphosis and segmental subluxation deterioration beyond walking age. Surgical stabilisation of the spine can be reserved for severe progressive deformities unresponsive to conservative treatment.

Cite this article: Bone Joint J 2015;97-B:982–7.

The December 2013 Spine Roundup³⁶⁰ looks at: Just how common is lumbar spinal stenosis?; How much will they bleed?; C5 palsy associated with stenosis; Atlanto-axial dislocations revisited; 3D predictors of progression in scoliosis; No difference in outcomes by surgical approach for fusion; Cervical balance changes after thoracolumbar surgery; and spinal surgeons first in space.

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.

The augmentation of fixation with bone cement is increasingly being used in the treatment of severe osteoporotic fractures. We investigated the influence of bone quality on the mechanics of augmentation of plate fixation in a distal femoral fracture model (AO 33 A3 type). Eight osteoporotic and eight non-osteoporotic femoral models were randomly assigned to either an augmented or a non-augmented group. Fixation was performed using a locking compression plate. In the augmented group additionally 1 ml of bone cement was injected into the screw hole before insertion of the screw. Biomechanical testing was performed in axial sinusoidal loading. Augmentation significantly reduced the cut-out distance in the osteoporotic models by about 67% (non-augmented mean 0.30 mm (sd 0.08) vs augmented 0.13 mm (sd 0.06); p = 0.017). There was no statistical reduction in this distance following augmentation in the non-osteoporotic models (non-augmented mean 0.15 mm (sd 0.02) vs augmented 0.15 mm (sd 0.07); p = 0.915). In the osteoporotic models, augmentation significantly increased stability (p = 0.017).

Cite this article: Bone Joint J 2013;95-B:1406–9.

The June 2015 Knee Roundup360 looks at: Cruciate substituting versus retaining knee replacement; What’s behind the psychology of anterior cruciate ligament (ACL) reconstruction?; Is there a difference in total knee arthroplasty risk of revision in highly crosslinked versus conventional polyethylene?; Unicompartmental knee arthroplasty: is age the missing variable?; Satisfaction rates following total knee arthroplasty; Is knee alignment dynamic?; Unicompartmental knee arthroplasty: cemented or cementless?; Can revision knee services pay?

Worldwide rates of primary and revision total knee arthroplasty (TKA) are rising due to increased longevity of the population and the burden of osteoarthritis.

Revision TKA is a technically demanding procedure generating outcomes which are reported to be inferior to those of primary knee arthroplasty, and with a higher risk of complication. Overall, the rate of revision after primary arthroplasty is low, but the number of patients currently living with a TKA suggests a large potential revision healthcare burden.

Many patients are now outliving their prosthesis, and consideration must be given to how we are to provide the necessary capacity to meet the rising demand for revision surgery and how to maximise patient outcomes.

The purpose of this review was to examine the epidemiology of, and risk factors for, revision knee arthroplasty, and to discuss factors that may enhance patient outcomes.

Cite this article: Bone Joint J 2015; 97-B:723–8.