We evaluated the accuracy of augmented reality (AR)-based navigation assistance through simulation of bone tumours in a pig femur model. We developed an AR-based navigation system for bone tumour resection, which could be used on a tablet PC. To simulate a bone tumour in the pig femur, a cortical window was made in the diaphysis and bone cement was inserted. A total of 133 pig femurs were used and tumour resection was simulated with AR-assisted resection (164 resection in 82 femurs, half by an orthropaedic oncology expert and half by an orthopaedic resident) and resection with the conventional method (82 resection in 41 femurs). In the conventional group, resection was performed after measuring the distance from the edge of the condyle to the expected resection margin with a ruler as per routine clinical practice.Objectives
Methods
To assess the accuracy of patient-specific instruments (PSIs) CT scans were obtained from five female cadaveric pelvises. Five osteotomies were designed using Mimics software: sacroiliac, biplanar supra-acetabular, two parallel iliopubic and ischial. For cases of the left hemipelvis, PSIs were designed to guide standard oscillating saw osteotomies and later manufactured using 3D printing. Osteotomies were performed using the standard manual technique in cases of the right hemipelvis. Post-resection CT scans were quantitatively analysed. Student’s Objectives
Methods
This paper aims to provide evidence-based guidance for the general orthopaedic surgeon faced with the presentation of a potential soft tissue sarcoma in an extremity.
A poor response to chemotherapy (≤ 90% necrosis)
for osteosarcomas leads to poorer survival and an increased risk of
local recurrence, particularly if there is a close margin of excision.
We evaluated whether amputation confers any survival benefit over
limb salvage surgery (LSS) with narrow margins in patients who respond
poorly to chemotherapy. We only analysed patients with an osteosarcoma of the limb, a
poor response to chemotherapy and close margins on LSS (marginal/intralesional)
or primary amputation: 360 patients (36 LSS (intralesional margins),
197 LSS (marginal margins) and 127 amputations) were included. Local
recurrence developed in 13 (36%) following LSS with intralesional
margins, and 39 (20%) following LSS with marginal margins. There
was no local recurrence in patients who underwent amputation. The
five-year survival for all patients was 41% (95% confidence interval
(CI) 35 to 46), but for those treated by LSS with marginal margins
was 46.2% (95% CI 38 to 53), 36.3% (95% CI 27 to 45) for those treated
by amputation, and 28% (95 CI 14 to 44) for those treated by LSS
with intralesional margins. Patients who had LSS and then developed
local recurrence as a first event had the same survival as those
who had primary amputation without local recurrence. Prophylactic
adjuvant radiotherapy was used in 40 patients but had no discernible
effect in preventing local recurrence. Although amputation offered better local control, it conferred
no clear survival benefit over LSS with marginal margins in these
patients with a poor overall prognosis. Cite this article:
The aim of this study was to evaluate the prognostic
and therapeutic factors which influence the oncological outcome
of parosteal osteosarcoma. A total of 80 patients with a primary parosteal osteosarcoma
were included in this retrospective study. There were 51 females
and 29 males with a mean age of 29.9 years (11 to 78). The mean follow-up was 11.2 years (1 to 40). Overall survival
was 91.8% at five years and 87.8% at ten years. Local recurrence
occurred in 14 (17.5%) patients and was associated with intralesional
surgery and a large volume of tumour. On histological examination,
80% of the local recurrences were dedifferentiated high-grade tumours.
A total of 12 (14.8%) patients developed pulmonary metastases, of
whom half had either a dedifferentiated tumour or a local recurrence.
Female gender and young age were good prognostic factors. Local
recurrence was a poor prognostic factor for survival. Medullary
involvement or the use of chemotherapy had no impact on survival. The main goal in treating a parosteal osteosarcoma must be to
achieve a wide surgical margin, as inadequate margins are associated
with local recurrence. Local recurrence has a significant negative
effect on survival, as 80% of the local recurrences are high-grade
dedifferentiated tumours, and half of these patients develop metastases. The role of chemotherapy in the treatment of parosteal osteosarcoma
is not as obvious as it is in the treatment of conventional osteosarcoma.
The mainstay of treatment is wide local excision. Cite this article:
The October 2015 Oncology Roundup360 looks at: Radiotherapy for the radioresistant; Multiple hereditary exostosis; The total femur as a limb salvage option; Survival prediction in osteosarcoma; What happens when chondrosarcoma recurs?; Thumbs up for vascularised fibular graft; Radiotherapy and survival; Musculoskeletal tumours in pregnancy
The October 2015 Children’s orthopaedics Roundup360 looks at: Radiographic follow-up of DDH; When the supracondylar goes wrong; Apophyseal avulsion fractures; The ‘pulled elbow’; Surgical treatment of active or aggressive aneurysmal bone cysts in children; Improving stability in supracondylar fractures; Biological reconstruction may be preferable in children’s osteosarcoma; The paediatric hip fracture
The use of robotics in arthroplasty surgery is expanding rapidly as improvements in the technology evolve. This article examines current evidence to justify the usage of robotics, as well as the future potential in this emerging field.
The widespread use of MRI has revolutionised
the diagnostic process for spinal disorders. A typical protocol
for spinal MRI includes T1 and T2 weighted sequences in both axial
and sagittal planes. While such an imaging protocol is appropriate
to detect pathological processes in the vast majority of patients,
a number of additional sequences and advanced techniques are emerging.
The purpose of the article is to discuss both established techniques
that are gaining popularity in the field of spinal imaging and to
introduce some of the more novel ‘advanced’ MRI sequences with examples
to highlight their potential uses. Cite this article:
The aim of this study was to compare the maximum
laxity conferred by the cruciate-retaining (CR) and posterior-stabilised
(PS) Triathlon single-radius total knee arthroplasty (TKA) for anterior
drawer, varus–valgus opening and rotation in eight cadaver knees
through a defined arc of flexion (0º to 110º). The null hypothesis
was that the limits of laxity of CR- and PS-TKAs are not significantly
different. The investigation was undertaken in eight loaded cadaver knees
undergoing subjective stress testing using a measurement rig. Firstly
the native knee was tested prior to preparation for CR-TKA and subsequently
for PS-TKA implantation. Surgical navigation was used to track maximal
displacements/rotations at 0º, 30º, 60º, 90º and 110° of flexion.
Mixed-effects modelling was used to define the behaviour of the
TKAs. The laxity measured for the CR- and PS-TKAs revealed no statistically
significant differences over the studied flexion arc for the two
versions of TKA. Compared with the native knee both TKAs exhibited
slightly increased anterior drawer and decreased varus-valgus and
internal-external roational laxities. We believe further study is required
to define the clinical states for which the additional constraint
offered by a PS-TKA implant may be beneficial. Cite this article:
Pigmented villonodular synovitis (PVNS) is a
rare proliferative process of the synovium which most commonly affects
the knee and occurs in either a localised (LPVNS) or a diffuse form
(DPVNS). The effect of different methods of surgical synovectomy
and adjuvant radiotherapy on the rate of recurrence is unclear.
We conducted a systematic review and identified 35 observational
studies in English which reported the use of surgical synovectomy
to treat PVNS of the knee. A meta-analysis included 630 patients, 137 (21.8%) of whom had
a recurrence after synovectomy. For patients with DPVNS, low-quality
evidence found that the rate of recurrence was reduced by both open
synovectomy (odds ration (OR) = 0.47; 95% CI 0.25 to 0.90; p = 0.024)
and combined open and arthroscopic synovectomy (OR = 0.19, 95% CI
= 0.06 to 0.58; p = 0.003) compared with arthroscopic surgery. Very
low-quality evidence found that the rate of recurrence of DPVNS
was reduced by peri-operative radiotherapy (OR = 0.31, 95% CI 0.14
to 0.70; p = 0.01). Very low-quality evidence suggested that the
rate of recurrence of LPVNS was not related to the surgical approach. This meta-analysis suggests that open synovectomy or synovectomy
combined with peri-operative radiotherapy for DPVNS is associated
with a reduced rate of recurrence. Large long-term prospective multicentre
observational studies, with a focus on both rate of recurrence and
function, are required to confirm these findings. Cite this article:
We investigated the clinical outcome of internal
fixation for pathological fracture of the femur after primary excision of
a soft-tissue sarcoma that had been treated with adjuvant radiotherapy. A review of our database identified 22 radiation-induced fractures
of the femur in 22 patients (seven men, 15 women). We noted the
mechanism of injury, fracture pattern and any complications after
internal fixation, including nonunion, hardware failure, secondary
fracture or deep infection. The mean age of the patients at primary excision of the tumour
was 58.3 years (39 to 86). The mean time from primary excision to
fracture was 73.2 months (2 to 195). The mean follow-up after fracture
fixation was 65.9 months (12 to 205). Complications occurred in
19 patients (86%). Nonunion developed in 18 patients (82%), of whom
11 had a radiological nonunion at 12 months, five a nonunion and
hardware failure and two an infected nonunion. One patient developed
a second radiation-associated fracture of the femur after internal
fixation and union of the initial fracture. A total of 13 patients
(59%) underwent 24 revision operations. Internal fixation of a pathological fracture of the femur after
radiotherapy for a soft-tissue sarcoma has an extremely high rate
of complication and requires specialist attention. Cite this article:
