Polymethylmethacrylate remains one of the most enduring materials in orthopaedic surgery. It has a central role in the success of total joint replacement and is also used in newer techniques such as percutaneous vertebroplasty and kyphoplasty.

This article describes the current uses and limitations of polymethylmethacrylate in orthopaedic surgery. It focuses on its mechanical and chemical properties and links these to its clinical performance. The behaviour of antibiotic-loaded bone cement are discussed, together with areas of research that are now shedding light upon the behaviour of this unique biomaterial.

In this study we present our experience with four generations of uncemented total knee arthroplasty (TKA) from Smith & Nephew: Tricon M, Tricon LS, Tricon II and Profix, focusing on the failure rates correlating with each design change. Beginning in 1984, 380 Tricon M, 435 Tricon LS, 305 Tricon 2 and 588 Profix were implanted by the senior author. The rate of revision for loosening was 1.1% for the Tricon M, 1.1% for the Tricon LS, 0.5% for the Tricon 2 with a HA coated tibial component, and 1.3% for the Profix TKA. No loosening of the femoral component was seen with the Tricon M, Tricon LS or Tricon 2, with no loosening seen of the tibial component with the Profix TKA. Regarding revision for wear, the incidence was 13.1% for the Tricon M, 6.6% for the Tricon LS, 2.3% for the Tricon 2, and 0% for the Profix. These results demonstrate that improvements in the design of uncemented components, including increased polyethylene thickness, improved polyethylene quality, and the introduction of hydroxyapatite coating, has improved the outcomes of uncemented TKA over time.

In the UK we have many surgeon inventors – surgeons who innovate and create new ways of doing things, who invent operations, who design new instruments to facilitate surgery or design new implants for using in patients. However truly successful surgeon inventors are a rare breed and they need to develop additional knowledge and skills during their career in order to push forward their devices and innovations. This article reviews my own experiences as a surgeon inventor and the highs and lows over the whole of my surgical career.

We used a goat model of a contaminated musculoskeletal defect to determine the effectiveness of rapidly-resorbing calcium-sulphate pellets containing amikacin to reduce the local bacterial count. Our findings showed that this treatment eradicated the bacteria quickly, performed as well as standard polymethylmethacrylate mixed with an antibiotic and had many advantages over the latter. The pellets were prepared before surgery and absorbed completely. They released all of the antibiotic and did not require a subsequent operation for their removal. Our study indicated that locally administered antibiotics reduced bacteria within the wound rapidly. This method of treatment may have an important role in decreasing the rate of infection in contaminated wounds.

In 2006, approximately 1.3 million peer-reviewed scientific articles were published, aided by a large rise in the number of available scientific journals from 16 000 in 2001 to 23 750 by 2006. Is this evidence of an explosion in scientific knowledge or just the accumulation of wasteful publications and junk science? Data show that only 45% of the articles published in the 4500 top scientific journals are cited within the first five years of publication, a figure that is dropping steadily. Only 42% receive more than one citation. For better or for worse, “Publish or Perish” appears here to stay as the number of published papers becomes the basis for selection to academic positions, for tenure and promotions, a criterion for the awarding of grants and also the source of funding for salaries. The high pressure to publish has, however, ushered in an era where scientists are increasingly conducting and publishing data from research performed with ‘questionable research practices’ or even committing outright fraud. The few cases which are reported will in fact be the tip of an iceberg and the scientific community needs to be vigilant against this corruption of science.

Between November 1994 and June 1999, 35 patients referred to our Problem Fracture Service with chronic diaphyseal osteomyelitis were treated using a closed double-lumen suction irrigation system after reaming and arthroscopic debridement of the intramedullary canal. This is a modified system based on that of Lautenbach.

Between June and July 2007 the patients were reviewed by postal questionnaire and telephone and from the case notes. At a mean follow-up of 101 months (2 to 150), 26 had no evidence of recurrence and four had died from unrelated causes with no evidence of recurrent infection. One had been lost to follow-up at two months and was therefore excluded. Four had persisting problems with sinus discharge and one had his limb amputated for recurrent metaplastic change.

Our results represent a clearance of infection of 85.3% (29 of 34), with recurrence in 11.8% (4 of 34). They are comparable to the results of the Papineau and Belfast techniques, but with considerably less surgical insult to the patient.

The lateral compartment is predominantly affected in approximately 10% of patients with osteoarthritis of the knee. The anatomy, kinematics and loading during movement differ considerably between medial and lateral compartments of the knee. This in the main explains the relative protection of the lateral compartment compared with the medial compartment in the development of osteoarthritis. The aetiology of lateral compartment osteoarthritis can be idiopathic, usually affecting the femur, or secondary to trauma commonly affecting the tibia. Surgical management of lateral compartment osteoarthritis can include osteotomy, unicompartmental knee replacement and total knee replacement. This review discusses the biomechanics, pathogenesis and development of lateral compartment osteoarthritis and its management.

Cite this article: Bone Joint J 2013;95-B:436–44.

This study was designed to test the hypothesis that the sensory innervation of bone might play an important role in sensing and responding to low-intensity pulsed ultrasound and explain its effect in promoting fracture healing. In 112 rats a standardised mid-shaft tibial fracture was created, supported with an intramedullary needle and divided into four groups of 28. These either had a sciatic neurectomy or a patellar tendon resection as control, and received the ultrasound or not as a sham treatment. Fracture union, callus mineralisation and remodelling were assessed using plain radiography, peripheral quantitative computed tomography and histomorphology.

Daily ultrasound treatment significantly increased the rate of union and the volumetric bone mineral density in the fracture callus in the neurally intact rats (p = 0.025), but this stimulating effect was absent in the rats with sciatic neurectomy. Histomorphology demonstrated faster maturation of the callus in the group treated with ultrasound when compared with the control group. The results supported the hypothesis that intact innervation plays an important role in allowing low-intensity pulsed ultrasound to promote fracture healing.

Medium-term survivorship of the Oxford phase 3 unicompartmental knee replacement (UKR) has not yet been established in an Asian population. We prospectively evaluated the outcome of 400 phase 3 Oxford UKRs in 320 Korean patients with a mean age at the time of operation of 69 years (48 to 82). The mean follow-up was 5.2 years (1 to 10). Clinical and radiological assessment was carried out pre- and post-operatively. At five years, the mean Knee Society knee and functional scores had increased significantly from 56.2 (30 to 91) pre-operatively to 87.2 (59 to 98) (p = 0.034) and from 59.2 (30 to 93) to 88.3 (50 to 100) (p = 0.021), respectively. The Oxford knee score increased from a mean of 25.8 (12 to 39) pre-operatively to 39.8 (25 to 58) at five years (p = 0.038). The ten-year survival rate was 94% (95% confidence interval 90.1 to 98.0). A total of 14 UKRs (3.5%) required revision. The most common reason for revision was dislocation of the bearing in 12 (3%). Conversion to a total knee replacement was required in two patients who developed osteoarthritis of the lateral compartment.

This is the largest published series of UKR in Korean patients. It shows that the mid-term results after a minimally invasive Oxford phase 3 UKR can yield satisfactory clinical and functional results in this group of patients.

The April 2012 Trauma Roundup³⁶⁰ looks at fibula-pro-tibia plating, galeazzi fractures, distal radial fractures in the over 65s, transverse sacral fractures, acute dislocation of the knee, posterior malleolar fractures, immobilising the broken scaphoid, the terrible triad, lower limb amputation after trauma, and whiplash injuries

This single-blinded randomised controlled trial investigated whether one design of mobile-bearing (MB) total knee replacement (TKR) has any advantage over a fixed-bearing (FB) design on long-term fixation as measured by radiostereometry. The amount of wear underneath the mobile bearing was also evaluated. A series of 42 knees was randomised to MB or FB tibial components with appropriate polyethylene inserts and followed for between ten and 12 years, or until the death of the patient. The polyethylene in the MB group was superior in that it was gamma-irradiated in inert gas and was calcium-stearate free; the polyethylene in the FB group was gamma-irradiated in air and contained calcium stearate. In theory this should be advantageous to the wear rate of the MB group. At final follow-up the overall mean migration was 0.75 mm (sd 0.76) in the MB group and 0.66 mm (sd 0.4) in the FB group, with the FB group demonstrating more posterior tilt and the MB group more internal rotation. In the FB group there was one revision for aseptic loosening, but none in the MB group. There were no significant differences in clinical or radiological scores.

For the MB group, the mean linear wear rate on the under-surface was 0.026 mm/year (sd 0.014). This was significantly smaller than the wear rate of 0.11 mm/year (sd 0.06) in the MB between femur and polyethylene (p < 0.001). Nevertheless, even in a best-case setting the mobile bearings of this TKR design had no apparent advantage in terms of fixation over the FB knee prosthesis at ten to 12 years. The wear underneath the mobile bearing was small and is unlikely to be clinically relevant.

Spinal stenosis and disc herniation are the two most frequent causes of lumbosacral nerve root compression. This can result in muscle weakness and present with or without pain. The difficulty when managing patients with these conditions is knowing when surgery is better than non-operative treatment: the evidence is controversial. Younger patients with a lesser degree of weakness for a shorter period of time have been shown to respond better to surgical treatment than older patients with greater weakness for longer. However, they also constitute a group that fares better without surgery. The main indication for surgical treatment in the management of patients with lumbosacral nerve root compression should be pain rather than weakness.

The aim of this review is to evaluate the current available literature evidencing on peri-articular hip endoscopy (the third compartment). A comprehensive approach has been set on reports dealing with endoscopic surgery for recalcitrant trochanteric bursitis, snapping hip (or coxa-saltans; external and internal), gluteus medius and minimus tears and endoscopy (or arthroscopy) after total hip arthroplasty. This information can be used to trigger further research, innovation and education in extra-articular hip endoscopy.

Incomplete avulsion of the proximal hamstrings can be a severely debilitating injury that causes weakness, pain while sitting and inability to run. The results of the surgical treatment of 23 consecutive patients with such injuries at least two years after surgery are described. The surgery consisted of the repair of the hamstrings directly onto the ischial tuberosity. At review, using a visual analogue scale (VAS, 0 to 100), pain while sitting improved from a mean of 40 (0 to 100) to 64 (0 to 100) (p = 0.024), weakness from a mean of 39 (0 to 90) to 76 (7 to 100) (p = 0.0001) and the ability to run from a mean of 24 (0 to 88) to 64 (0 to 95) (p = 0.0001). According to a VAS, satisfaction was rated at a mean of 81 (0 to 100) and 20 patients (87%) would have the same procedure again. Hamstring strength measured pre- and post-operatively had improved significantly from a mean of 64% (0% to 95%) to 88% (50% to 114%) compared with the normal side.

Most of these patients with symptomatic incomplete hamstring avulsions unresponsive to conservative treatment had an improved outcome after surgical repair.

The August 2012 Knee Roundup³⁶⁰ looks at: meniscal defects and a polyurethane scaffold; which is best between a single or double bundle; OA of the knee; how to resolve anterior knee pain; whether yoga can be bad for your menisci; metal ions in the serum; whether ACI is any good; the ACL; whether hyaluronic acid delays collagen degradation; and hyaluronan and patellar tendinopathy.

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

Objectives

To evaluate the neck strength of school-aged rugby players, and to define the relationship with proxy physical measures with a view to predicting neck strength.

The open blast fracture of the pelvis is considered to be the most severe injury within the spectrum of battlefield trauma. We report our experience of 29 consecutive patients who had sustained this injury in Afghanistan between 2008 and 2010. Their median new injury severity score (NISS) was 41 (8 to 75), and mean blood requirement in the first 24 hours was 60.3 units (0 to 224). In addition to their orthopaedic injury, six had an associated vascular injury, seven had a bowel injury, 11 had a genital injury and seven had a bladder injury. In all, eight fractures were managed definitively with external fixation and seven required internal fixation. Of those patients who underwent internal fixation, four required removal of metalwork for infection. Faecal diversion was performed in nine cases. The median length of hospital stay following emergency repatriation to the United Kingdom was 70.5 days (5 to 357) and the mean total operating time was 29.6 hours (5 to 187). At a mean follow-up of 20.3 months (13.2 to 29.9), 24 patients (82.8%) were able to walk and 26 (89.7%) had clinical and radiological evidence of stability of the pelvic ring.

As a result of the increase in terrorism, injuries that were previously confined exclusively to warfare can now occur anywhere, with civilian surgeons who are involved in trauma care potentially required to manage similar injuries. Our study demonstrates that the management of this injury pattern demands huge resources and significant multidisciplinary input. Given the nature of the soft-tissue injury, we would advocate external fixation as the preferred management of these fractures. With the advent of emerging wound and faecal management techniques, we do not believe that faecal diversion is necessary in all cases.

Rupture of the tendo Achillis is a common injury with a rising incidence. Traditionally the key question following this injury has been whether or not to operate. However a contemporary Cochrane review highlighted that the method of rehabilitation may also have an important contribution to the outcome. Since this review, various early weight-bearing rehabilitation protocols have been described. Currently evidence points to the use of early functional rehabilitation, regardless of operative or non-operative management. However, there is no consensus on which exact functional rehabilitation protocol should be used. Future research should be directed towards improving our understanding of how the different rehabilitative components interact in the tendo Achillis as it heals.

A total of 20 pairs of fresh-frozen cadaver femurs were assigned to four alignment groups consisting of relative varus (10° and 20°) and relative valgus (10° and 20°), 75 composite femurs of two neck geometries were also used. In both the cadaver and the composite femurs, placing the component in 20° of valgus resulted in a significant increase in load to failure. Placing the component in 10° of valgus had no appreciable effect on increasing the load to failure except in the composite femurs with varus native femoral necks. Specimens in 10° of varus were significantly weaker than the neutrally-aligned specimens.

The results suggest that retention of the intact proximal femoral strength occurs at an implant angulation of ≥ 142°. However, the benefit of extreme valgus alignment may be outweighed in clinical practice by the risk of superior femoral neck notching, which was avoided in this study.