The purpose of this study was to measure the radiological parameters of femoral component alignment of the Oxford Phase 3 unicompartmental knee replacement (UKR), and evaluate their effect on clinical outcome. Multiple regression analysis was used to examine the relative contributions of the radiological assessment of femoral component alignment in 189 consecutive UKRs performed by a single surgeon. The American Knee Society scores were compared between groups, defined as being within or outside recommended tolerances of the position of the femoral component. For the flexion/extension position 21 UKRs (11.1%) lay outside the recommended limits, and for posterior overhang of the femoral component nine (4.8%) lay outside the range. The pre-operative hip/knee/ankle (HKA) angle, narrowest canal distance from the distal femoral entry point of the alignment jig and coronal entry-point position had significant effects on the flexion/extension position. Pre-operative HKA angle had a significant influence on posterior overhang of the femoral component. However, there was no significant difference in American Knee Society scores relative to the position of the femoral component.

Symptomatic and asymptomatic deep-vein thrombosis (DVT) is a common complication of knee replacement, with an incidence of up to 85% in the absence of prophylaxis. National guidelines for thromboprophylaxis in knee replacement are derived from total knee replacement (TKR) data. No guidelines exist specific to unicompartmental knee replacement (UKR). We investigated whether the type of knee arthroplasty (TKR or UKR) was related to the incidence of DVT and discuss the applicability of existing national guidelines for prophylaxis following UKR.

Data were collected prospectively on 3449 knee replacements, including procedure type, tourniquet time, surgeon, patient age, use of drains and gender. These variables were related to the incidence of symptomatic DVT.

The overall DVT rate was 1.6%. The only variable that had an association with DVT was operation type, with TKR having a higher incidence than UKR (2.2% versus 0.3%, p < 0.001). These data show that the incidence of DVT after UKR is both clinically and statistically significantly lower than that after TKR.

TKR and UKR patients have different risk profiles for symptomatic DVT. The risk-benefit ratio for TKR that has been used to produce national guidelines may not be applicable to UKR. Further research is required to establish the most appropriate form of prophylaxis for UKR.

This article reviews the current knowledge of the intervertebral disc (IVD) and its association with low back pain (LBP). The normal IVD is a largely avascular and aneural structure with a high water content, its nutrients mainly diffusing through the end plates. IVD degeneration occurs when its cells die or become dysfunctional, notably in an acidic environment. In the process of degeneration, the IVD becomes dehydrated and vascularised, and there is an ingrowth of nerves. Although not universally the case, the altered physiology of the IVD is believed to precede or be associated with many clinical symptoms or conditions including low back and/or lower limb pain, paraesthesia, spinal stenosis and disc herniation.

New treatment options have been developed in recent years. These include biological therapies and novel surgical techniques (such as total disc replacement), although many of these are still in their experimental phase. Central to developing further methods of treatment is the need for effective ways in which to assess patients and measure their outcomes. However, significant difficulties remain and it is therefore an appropriate time to be further investigating the scientific basis of and treatment of LBP.

We report a prospective single-blind controlled study of the incidence of early wound infection after internal fixation for trauma in 609 patients, of whom 132 were HIV-positive. Wounds were assessed for healing using the ASEPSIS score. There was no significant difference in the rate of infection between HIV-positive and HIV-negative patients undergoing clean surgery (4.2% vs 6%, respectively; p = 0.65). HIV-positive patients did not receive additional antibiotic prophylaxis or antiretroviral therapy as part of their management. The difference in the rate of infection between HIV-positive and HIV-negative patients with an open fracture or other contamination was not significant (33% vs 15%, respectively; p = 0.064). There was no relationship between CD4 count and infection rate. HIV status did not significantly influence the number of secondary surgical procedures (p = 0.183) or the likelihood of developing chronic osteomyelitis (p = 0.131). Although previous contamination from the time of injury was a risk factor for infection in mal- and nonunions, it was not significantly increased in HIV-positive patients (p = 0.144).

We conclude that clean implant surgery in HIV-positive patients is safe, with no need for additional prophylaxis.

The August 2012 Research Roundup³⁶⁰ looks at: PRP and chondrogenic differentiation; basic fibroblast growth factor; whether glucosamine works; randomised trials; ossification of the ligamentum flavum; treadmill running; inhibiting BMP antagonists; and whether NSAIDs delay union after all.

The August 2012 Spine Roundup³⁶⁰ looks at: neural tissue and polymerising bone cement; a new prognostic score for spinal metastases from prostatic tumours; recovery after spinal decompression; spinal tuberculosis; unintended durotomy at spinal surgery; how carrying a load on your head can damage the cervical spine; and how age changes your lumbar spine.

The August 2012 Foot & Ankle Roundup³⁶⁰ looks at: calcaneocuboid distraction arthrodesis with allograft for acquired flatfoot; direct repair of the plantar plate; thromboembolism after fixation of the fractured ankle; weight loss after ankle surgery; Haglund’s syndrome and three-portal endoscopic surgery; Keller’s procedure; arthroscopy of the first MTPJ; and Doppler spectra in Charcot arthropathy.

Objectives

In order to elucidate the influence of sympathetic nerves on lumbar radiculopathy, we investigated whether sympathectomy attenuated pain behaviour and altered the electrical properties of the dorsal root ganglion (DRG) neurons in a rat model of lumbar root constriction.

Objectives

To assess the effectiveness of a modified tibial tubercle osteotomy as a treatment for arthroscopically diagnosed chondromalacia patellae.

We present our early experience of arthroscopic reduction of the dislocated hip in very young infants with developmental dysplasia of the hip (DDH).

Eight dislocated hips, which had failed attempts at closed reduction, were treated by arthroscopy of the hip in five children with a mean age of 5.8 months (4 to 7). A two-portal technique was used, with a medial sub-adductor portal for a 2.7 mm cannulated system with a 70° arthroscope and an anterolateral portal for the instruments. Following evaluation of the key intra-articular structures, the hypertrophic ligamentum teres and acetabular pulvinar were resected, and a limited release of the capsule was performed prior to reduction of the hip. All hips were reduced by a single arthroscopic procedure, the reduction being confirmed on MRI scan. None of the hips had an inverted labrum. The greatest obstacle to reduction was a constriction of the capsule. At a mean follow-up of 13.2 months (9 to 24), all eight hips remained stable. Three developed avascular necrosis. The mean acetabular index decreased from 35.5° (30° to 40°) pre-operatively to 23.3° (17° to 28°).

This study demonstrates that arthroscopic reduction is feasible using two standardised portals. Longer follow-up studies are necessary to evaluate the functional results.

Between 1978 and 1997 all newborns in the Austrian province of Tyrol were reviewed regarding hip dysplasia and related surgery. This involved a mean of 8257 births per year (7766 to 8858). Two observation periods were determined: 1978 to 1982 (clinical examination alone) and 1993 to 1997 (clinical examination and universal ultrasound screening). A retrospective analysis compared the number and cost of interventions due to hip dysplasia in three patient age groups: A, 0 to < 1.5 years; B, ≥ 1.5 to < 15 years; and C, ≥ 15 to < 35 years.

In group A, there was a decrease in hip reductions from a mean of 25.2 (sd 2.8) to 7.0 (sd 1.4) cases per year. In group B, operative procedures decreased from a mean of 17.8 (sd 3.5) to 2.6 (sd 1.3) per year. There was a 75.9% decrease in the total number of interventions for groups A and B.

An increase of €57 000 in the overall cost per year for the second period (1993 to 1997) was seen, mainly due to the screening programme. However, there was a marked reduction in costs of all surgical and non-surgical treatments for dysplastic hips from €410 000 (1978 to 1982) to €117 000 (1993 to 1997). We believe the small proportional increase in costs of the universal ultrasound screening programme is justifiable as it was associated with a reduction in the number of non-surgical and surgical interventions. We therefore recommend universal hip ultrasound screening for neonates.

Patient-reported outcome measures (PROMs) are increasingly being used to assess functional outcome and patient satisfaction. They provide a framework for comparisons between surgical units, and individual surgeons for benchmarking and financial remuneration. Better performance may bring the reward of more customers as patients and commissioners seek out high performers for their elective procedures. Using National Joint Registry (NJR) data linked to PROMs we identified 22 691 primary total knee replacements (TKRs) undertaken for osteoarthritis in England and Wales between August 2008 and February 2011, and identified the surgical factors that influenced the improvements in the Oxford knee score (OKS) and EuroQol-5D (EQ-5D) assessment using multiple regression analysis. After correction for patient factors the only surgical factors that influenced PROMs were implant brand and hospital type (both p < 0.001). However, the effects of surgical factors upon the PROMs were modest compared with patient factors. For both the OKS and the EQ-5D the most important factors influencing the improvement in PROMs were the corresponding pre-operative score and the patient’s general health status. Despite having only a small effect on PROMs, this study has shown that both implant brand and hospital type do influence reported subjective functional scores following TKR. In the current climate of financial austerity, proposed performance-based remuneration and wider patient choice, it would seem unwise to ignore these effects and the influence of a range of additional patient factors.

The purpose of this prospective study was to evaluate the long-term clinical and radiological outcomes of revision of the femoral component of a total hip replacement using impaction bone grafting. Femoral revision with an impacted allograft was performed on 29 patients (31 hips). In all, 21 hips (68%) had grade III or IV femoral defects according to the Endo-Klinik classification. A total of 11 patients (12 hips) died before the ten-year follow-up period. Of the remaining patients, 18 patients (19 hips) were followed for 10 to 15 years; three further patients died during this time. None of the 31 stems underwent further revision of their stem. However, four stems showed extensive subsidence (> 15 mm). One of these patients had a femoral fracture that required fixation. Three other patients had a femoral fracture, two of which required fixation and the other was treated conservatively. Patients with a femoral fracture and/or severe subsidence had significantly more grade IV defects (six of seven hips; p = 0.004). One patient needed a closed reduction for dislocation.

Impaction allografting in revision hip surgery gives good long-term results for femora with grades I, II and III Endo-Klinik-classified defects. Extensive subsidence and femoral fractures were seen mainly in patients with grade IV damaged femora.

For the treatment of ununited fractures, we developed a system of delivering magnetic labelled mesenchymal stromal cells (MSCs) using an extracorporeal magnetic device. In this study, we transplanted ferucarbotran-labelled and luciferase-positive bone marrow-derived MSCs into a non-healing femoral fracture rat model in the presence of a magnetic field. The biological fate of the transplanted MSCs was observed using luciferase-based bioluminescence imaging and we found that the number of MSC derived photons increased from day one to day three and thereafter decreased over time. The magnetic cell delivery system induced the accumulation of photons at the fracture site, while also retaining higher photon intensity from day three to week four. Furthermore, radiological and histological findings suggested improved callus formation and endochondral ossification. We therefore believe that this delivery system may be a promising option for bone regeneration.

The April 2012 Shoulder & Elbow Roundup³⁶⁰ looks at katakori in Japan, frozen shoulder, if shoulder impingement actually exists, shoulder arthroscopy and suprascapular nerve blocks, why shoulder replacements fail, the infected elbow replacement, the four-part fracture, the acromion index, and arm transplantation

The April 2012 Spine Roundup³⁶⁰ looks at yoga for lower back pain, spinal tuberculosis, complications of spinal surgery, fusing the subaxial cervical spine, minimally invasive surgery and osteoporotic vertebral fractures, spinal surgery in the over 65s, and pain relief after spinal surgery

The April 2012 Wrist & Hand Roundup³⁶⁰ looks at releasing the trigger finger, function in the osteoarthritic hand, complex regional pain syndrome, arthroscopic ligamentoplasty for the injured scapholunate ligament, self-concept and upper limb deformities in children, wrist arthroscopy in children, internal or external fixation for the fractured distal radius, nerve grafting, splinting the PIPJ contracture, and finding the stalk of a dorsal wrist ganglion

We aimed to identify the incidence, outcome and prognostic factors associated with spindle cell sarcomas of bone (SCSB). We studied 196 patients with a primary non-metastatic tumour treated with the intent to cure. The results were compared with those of osteosarcoma patients treated at our hospital during the same period. The overall incidence of SCSB was 7.8% of all patients with a primary bone sarcoma. The five- and ten-year survival rates were 67.0% and 60.0%, respectively, which were better than those of patients with osteosarcoma treated over the same period. All histological subtypes had similar outcomes. On univariate analysis, factors that were significantly associated with decreased survival were age > 40 years, size > 8 cm, the presence of a pathological fracture, amputation, involved margins and a poor response to pre-operative chemotherapy. Multivariate analyses showed that age > 65 years, amputation and involved margins were all statistically significant prognostic factors. Involved margins and poor response to pre-operative chemotherapy were associated with an increased risk of local recurrence. SCSB has a better prognosis than osteosarcoma when matched for age. Most prognostic factors for osteosarcoma also seem to apply to SCSB. Patients with SCSB should be treated in the same way as patients of the same age with osteosarcoma.

The aim of this study was to identify the incidence of post-operative symptomatic deep-vein thrombosis (DVT), as well as the risk factors for and location of DVT, in 665 patients (701 ankles) who underwent primary total ankle replacement. All patients received low-molecular-weight heparin prophylaxis. A total of 26 patients (3.9%, 26 ankles) had a symptomatic DVT, diagnosed by experienced radiologists using colour Doppler ultrasound. Most thrombi (22 patients, 84.6%) were localised distally in the operated limb. Using a logistic multiple regression model we identified obesity, a previous venous thromboembolic event and the absence of full post-operative weight-bearing as independent risk factors for developing a symptomatic DVT.

The incidence of symptomatic DVT after total ankle replacement and use of low-molecular-weight heparin is comparable with that in patients undergoing total knee or hip replacement.

Infection remains a significant and common complication after joint replacement and there is debate about which contributing factors are important. Few studies have investigated the effect of the operating time on infection.

We collected data prospectively from 5277 hip and knee replacements which included the type of procedure, the operating time, the use of drains, the operating theatre, surgeon, age and gender. In a subgroup of 3449 knee replacements further analysis was carried out using the tourniquet time in place of the operating time. These variables were assessed by the use of generalised linear modelling against superficial, deep or joint-space post-operative infection as defined by the Australian Surgical-Site Infection criteria.

The overall infection rate was 0.98%. In the replacement data set both male gender (z = 3.097, p = 0.00195) and prolonged operating time (z = 4.325, p < 0.001) were predictive of infection. In the knee subgroup male gender (z = 2.250, p = 0.02447), a longer tourniquet time (z = 2.867, p = 0.00414) and total knee replacement (versus unicompartmental knee replacement) (z = −2.052, p = 0.0420) were predictive of infection.

These findings support the view that a prolonged operating time and male gender are associated with an increased incidence of infection. Steps to minimise intra-operative delay should be instigated, and care should be exercised when introducing measures which prolong the duration of joint replacement.