The August 2023 Research Roundup³⁶⁰ looks at: Can artificial intelligence improve the readability of patient education materials?; What is the value of radiology input during a multidisciplinary orthopaedic oncology conference?; Periprosthetic joint infection in patients with multiple arthroplasties; Orthopedic Surgery and Anesthesiology Surgical Improvement Strategies Project - Phase III outcomes; Knot tying in arthroplasty and arthroscopy causes lesions to surgical gloves: a potential risk of infection; Vascular calcification of the ankle in plain radiographs equals diabetes mellitus?

Aims. Despite numerous studies focusing on periprosthetic joint infections (PJIs), there are no robust data on the risk factors and timing of metachronous infections. Metachronous PJIs are PJIs that can arise in the same or other artificial joints after a period of time, in patients who have previously had PJI. Methods. Between January 2010 and December 2018, 661 patients with multiple joint prostheses in situ were treated for PJI at our institution. Of these, 73 patients (11%) developed a metachronous PJI (periprosthetic infection in patients who have previously had PJI in another joint, after a lag period) after a mean time interval of 49.5 months (SD 30.24; 7 to 82.9). To identify patient-related risk factors for a metachronous PJI, the following parameters were analyzed: sex; age; BMI; and pre-existing comorbidity. Metachronous infections were divided into three groups: Group 1, metachronous infections in ipsilateral joints; Group 2, metachronous infections of the contralateral lower limb; and Group 3, metachronous infections of the lower and upper limb. Results. We identified a total of 73 metachronous PJIs: 32 PJIs in Group 1, 38 in Group 2, and one in Group 3. The rate of metachronous infection was 11% (73 out 661 cases) at a mean of four years following first infection. Diabetes mellitus incidence was found significantly more frequently in the metachronous infection group than in non-metachronous infection group. The rate of infection in Group 1 (21.1%) was significantly higher (p = 0.049) compared to Groups 2 (6.2%) and 3 (3%). The time interval of metachronous infection development was shorter in adjacent joint infections. Concordance between the bacterium of the first PJI and that of the metachronous PJI in Group 1 (21/34) was significantly higher than Group 2 (13/38; p = 0.001). Conclusion. The findings of this study suggest that metachronous PJI occurs in more than one in ten patients with an index PJI. Female patients, diabetic patients, and patients with a polymicrobial index PJI are at significantly higher risk for developing a metachronous PJI. Furthermore, metachronous PJIs are significantly more likely to occur in an adjacent joint (e.g. ipsilateral hip and knee) as opposed to a more remote site (i.e. contralateral or upper vs lower limb). Additionally, adjacent joint PJIs occur significantly earlier and are more likely to be caused by the same bacteria as the index PJI. Cite this article: Bone Joint J 2023;105-B(3):294–300

Aims. We performed a systematic literature review to define features of patients, treatment, and biological behaviour of multicentric giant cell tumour (GCT) of bone. Methods. The search terms used in combination were “multicentric”, “giant cell tumour”, and “bone”. Exclusion criteria were: reports lacking data, with only an abstract; papers not reporting data on multicentric GCT; and papers on multicentric GCT associated with other diseases. Additionally, we report three patients treated under our care. Results. A total of 52 papers reporting on 104 patients were included in the analysis, with our addition of three patients. Multicentric GCT affected predominantly young people at a mean age of 22 years (10 to 62), manifesting commonly as metachronous tumours. The mean interval between the first and subsequent lesions was seven years (six months to 27 years). Synchronous lesions were observed in one-third of the patients. Surgery was curettage in 63% of cases (163 lesions); resections or amputation were less frequent. Systemic treatments were used in 10% (n = 14) of patients. Local recurrence and distant metastases were common. Conclusion. Multicentric GCT is rare, biologically aggressive, and its course is unpredictable. Patients with GCT should be followed indefinitely, and referred promptly if new symptoms, particularly pain, emerge. Denosumab can have an important role in the treatment. Cite this article: Bone Joint J 2022;104-B(12):1352–1361

Aims. Despite numerous studies on periprosthetic joint infections (PJI), there are no robust data on the risk factors and timing of metachronous infections. This study was performed to answer the following questions: 1) Is there any difference of manifestation time of metachronous PJIs between different localizations of multiple artificial joints? 2) Can we identify any specific risk factor for metachronous PJIs for different localizations of multiple artificial joints?. Methods. Between January 2010 and December 2018, 661 patients with more than one prosthetic joint at the time of PJI surgical treatment were recruited. Seventy-one developed metachronous PJI after a mean time interval of 101.4 months (range 37.5 to 161.5 months). The remaining patients were chosen as control group. The diagnosis of the PJI, including the metachronous PJI, was made according to the Muscoloskeletal Infection Society (MSIS) criteria. The metachronous infections were divided in group 1: metachronous infections in the same extremity (e.g. right hip and right knee); group 2: metachronous infections of the other extremity (e.g. right knee and left hip); group 3: metachronous infections of the lower extremity and upper extremity (e.g. right knee and left shoulder). Results. We identified 32 PJI cases in group 1, 38 in group 2 and 1 in group 3. Diabetes mellitus was found higher in the metachronous infections (p<0.05). Rate of same side infection was significantly higher compared to contralateral and upper and lower infection (p<0.05). Time interval of metachrononous infection development was faster in same-side infections. Same bacteria sample rate between primary PJI and metachronous PJI in same side infections (21/32) was significantly higher than in the contralateral PJI group (13/38, p<0.05). Conclusions. The current study underlined that the risk of metachronous infections are relatively high, particularly in the cases of prostheses on the same side

Aims

Cell-free DNA (cfDNA) and circulating tumour DNA (ctDNA) are used for prognostication and monitoring in patients with carcinomas, but their utility is unclear in sarcomas. The objectives of this pilot study were to explore the prognostic significance of cfDNA and investigate whether tumour-specific alterations can be detected in the circulation of sarcoma patients.

Introduction. Treatment of spinal metastatic disease has evolved with the advent of advanced interventional, surgical and radiation techniques. Spinal Oligometastatic disease is a low volume disease state where en bloc resection of the tumour, based on oncological principles, can achieve maximum local control (MLC). Hybrid therapy incorporating Separation surgery (>2mm clearance of the thecal sac) and Stereotactic Ablative Radiotherapy (SABR) offer an alternative approach to achieving MLC. Hybrid therapy is also a viable option in patients eligible for SBRT who have failed conventional radiation therapy. En-bloc surgery may be a suitable option for those patients who are ineligible for or have failed SBRT. A multidisciplinary approach is particularly important in the decision-making process for these patients. Metal free instrumentation is aiding the optimization of these surgeries. The authors present a supra-regional centre's experience in managing spinal oligometastases. Methods. Retrospective review of oligometastatic spinal disease at a supra-regional centre between 2017 and 2021. Demographics, operative course, complications and Instrument type are examined. Results. Demographics: 24 patients with mean age 53.8y (range 12–77), 44% (40y–59y), 40% (60y–69y); 51% Male. Histology: Breast, Renal and Sarcoma accounted for 16.7% each; Thyroid, Prostate and Chordoma accounted for 8.3% each. Primary disease 7%, Synchronous 15%, Metachronous 78%. Instrumentation: Carbon-fibre (85%), TiAl (11%), Non-Instrumented (3%). Separation Surgery (70%), En-bloc resection/Tomita surgery (30%); SABR/Proton Beam Planned: 70%. Average length of hospital stays 19.1 days; twenty patients required intensive care admission for an average 2.7 days. 30 Day Mortality 8.3% (n=2: COVID-19 during admission and ventriculitis post discharge), 1y Mortality – 16.7%, 3y Mortality – 25%; Synchronous Mortality 75% (n=3) at 3 years. 30 Day infection rate 3%; 1y infection rate 7%. 1 Non-instrumented case developed proximal junctional failure post proton beam therapy and required a vascularised fibular strut graft. 2-year Revision for Local Recurrence 5% (Revision at 23 months). Conclusion. There are very few case series of oligometastatic spinal disease due to the relatively new concept of adjuvant SABR and its limited availability. Solid tumours pre-dominated the histology in our series with metachronous disease being the most commonly operated disease state. 92% of cases were eligible for SABR. The majority (85%) of cases were performed with Carbon-fibre instrumentation and has been shown to be safe with no mechanical failures in this series. Infection rates are in keeping with patients requiring radical radiotherapy with 3% early and 7% late. 30-day mortality was 8.3%, 1y=16.7% and 25% at last follow up. Mortality, as expected, is highest within the synchronous disease group and should be operated on sparingly. With the current management strategy, there was no local recurrence at 1 year and excellent local recurrence rate at 2 years (5%). Although radical en bloc surgery carries significant morbidity, it should be considered in selective cases to achieve MLC. All Oligometastatic cases deserve extra consideration and specialist MDT as not all are suitable for SABR. Multimodal Hybrid therapy, incorporating less invasive surgical techniques and SABR, represents a paradigm shift in achieving MLC in oligometastatic spinal disease

Aims. The aim of this study was to identify factors that determine outcomes of treatment for patients with chondroblastic osteosarcomas (COS) of the limbs and pelvis. Patients and Methods. The authors carried out a retrospective review of prospectively collected data from 256 patients diagnosed between 1979 and 2015. Of the 256 patients diagnosed with COS of the pelvis and the limbs, 147 patients (57%) were male and 109 patients (43%) were female. The mean age at presentation was 20 years (0 to 90). Results. In all, 82% of the patients had a poor response to chemotherapy, which was associated with the presence of a predominantly chondroblastic component (more than 50% of tumour volume). The incidence of local recurrence was 15%. Synchronous or metachronous metastasis was diagnosed in 60% of patients. Overall survival was 51% and 42% after five and ten years, respectively. Limb localization and wide surgical margins were associated with a lower risk of local recurrence after multivariable analysis, while the response to chemotherapy was not. Local recurrence, advanced patient age, pelvic tumours, and large volume negatively influenced survival. Resection of pulmonary metastases was associated with a survival benefit in the limited number of patients in whom this was undertaken. Conclusion. COS demonstrates a poor response to chemotherapy and a high incidence of metastases. Wide resection is associated with improved local control and overall survival, while excision of pulmonary metastases is associated with improved survival in selected patients. Cite this article: Bone Joint J 2019;101-B:739–744

Aims

The purpose of this study was to clarify the clinical behaviour, prognosis, and optimum treatment of dedifferentiated low-grade osteosarcoma (DLOS) diagnosed based on molecular pathology.

All patients referred to our unit with previously untreated metastatic renal cancer were included in this review. We investigated likely prognostic factors including age, sex, site, synchronous or metachronous metastasis, stage of the disease and the type of treatment received. From 1976 until 2004, a total of 198 patients were treated by our unit for renal metastases. 15 patients were excluded because they were referred after failure of previous treatment or only had advice. 96 patients were already known to have renal metastasis with their diagnosis having been made between 0.2 and 17 years from the diagnosis of primary cancer (mean 4 years). 33 patients presented to us with a pathological fracture and were found to have renal cancer. A total of 54 patients had multiple metastases and 129 had a solitary metastasis. The cumulative survival from the time of diagnosis of the bone metastasis is 70 percent at 1 year, 40% at 3 years and 18% at 5 years. In patients with a solitary metastasis, the overall survival was 74% at 1 year and 45% at 3 years, whereas in patients with multiple metastases it was 55% at 1 year and 22% at 3 years. (p=0.02) In patients with a solitary metastasis treated by excision of the metastasis, the survival at 1 year was 86% as compared to 38% for those that were treated with just a local procedure. Cox multivariate analysis shows that survival was better in those with solitary metachronus metastasis who underwent a radical procedure. Conclusion. We recommend a radical procedure for patients who present with a solitary renal metastasis, particularly those with a disease-free interval of more than one year

Purpose: Giant cell tumor (GCT) of bone is a rare, usually benign, primary skeletal lesion. The disease’s clinical course may be complicated by local recurrence subsequent to surgical treatment or the development of benign pulmonary metastases. Intra-lesional curettage is the standard treatment of primary GCT of bone. However, the value of intralesional procedures in recurrent GCT has not been well established. Method: Forty-six patients with recurrent GCT of long bones treated between 1983 and 2005 were followed retrospectively. Minimum follow-up was three years; mean follow-up was 11.1 (±4.8) years. Results: Wide resections were performed in 18 patients. Intralesional, joint preserving procedures were performed in 28 patients. Subsequent recurrence occurred in nine patients (20%). Wide resection was performed if joint salvage was not achievable due to expansion of the tumor. Reconstructions following wide resection included arthroplasty (n=4), osteoarticular allograft (n=3), APC (n=1) and fibular autograft reconstruction of the wrist (n=3). Amputations were performed in two patients. Patients undergoing wide resections for local recurrence had a significantly smaller risk of subsequent recurrence as compared to patients treated with intra-lesional surgery (6% versus 32%, hazard ratio: 0.28, p< 0.05). In patients treated with intralesional surgery, application of polymethylmethacrylate (PMMA) in addition to local phenol treatment significantly reduced the risk of subsequent recurrence (PMMA + phenol: 7% vs. Phenol: 25%, hazard ratio: 0.23, p< 0.05). Soft tissue expansion was not associated with an increased risk of subsequent recurrence. At follow-up, all patients with subsequent recurrence were without local disease after additional intralesional surgery (n=3) or wide resection (n=5). Metachronous benign pulmonary metastases evolved in five cases. There was no correlation between the development of pulmonary metastases and the type of treatment of recurrent disease found. Conclusion: In recurrent disease of GCT of long bones and the possibility to salvage the adjacent joint intra-lesional surgery is the treatment of choice independent of whether soft tissue expansion is present. Intra-lesional surgery does not increase the risk of development benign pulmonary metastases. In cases with extensive tumor formation and without the possibility to preserve the adjacent joint wide resection has a high chance for long-term recurrence free disease

Enchondromatosis is a non-hereditary disease, characterised by the presence of multiple enchondromas. While Ollier Disease is typified by multiple enchondromas, in Maffucci Syndrome they are combined with haemangioma. Due to the rarity of these diseases, systematic studies on clinical behaviour providing information how to treat patients are lacking. This study intends to answer the following questions: What are predictive factors for developing chondrosarcoma? When is extensive surgery necessary? How often patients die due to dedifferentiation or metastasis?. Twelve institutes in eight countries participated in this descriptive retrospective EMSOS-study. 118 Patients with Ollier Disease and 15 patients with Maffucci Syndrome were included. Unilateral localization of disease was found in 60% of Ollier patients and 40% of patients with Maffucci Syndrome. One of the predictive factors for developing chondrosarcoma is the location of the enchondromas; the risk increases especially when enchondromas are located in the scapula (33%), humerus (18%), pelvis (26%) or femur (15%). For the phalanges, this risk is 14% in the hand and 16% in the feet. The decision whether or not to perform extensive surgery is difficult, especially in patients who suffer multiple chondrosarcomas. Malignant transformation was found in fourty-four patients with Ollier Disease (37%) and eight patients with Maffucci Syndrome (53%). Multiple synchronous or metachronous chondrosarcomas were found in 15 patients. Nine patients died (range 21–54 yrs). Seven of them died disease related due to pulmonary metastasis (2 humerus, 2 pelvis, 3 femur). Two patients died from glioma of the brain. In conclusion, one important predictive factor for developing chondrosarcoma is the location of the enchondromas; interestingly, only patients with chondrosarcoma outside the small bones died of their disease. In this series, no dedifferentiation of chondrosarcoma was seen. A first design flow-chart how to approach chondrosarcoma in patients with Ollier Disease and Maffucci Syndrome is in preparation

Purpose of study: To test the hypothesis that previous hip involvement leads to earlier presentation and a better outcome for the contra-lateral hip in bilateral Legg-Calve-Perthes’ disease (LCPD).

Method: Case notes and radiographs of 250 patients with LCPD treated by a single surgeon between 1984 and 2003 were retrospectively reviewed. Thirty three patients (4 girls: 29 boys) with a minimum 1 year follow-up were identified with bilateral involvement from a prospectively collected database. Patients were grouped according to age at presentation (Group A-< 6 years; Group B- 6–8 years; Group C-> 8 years). All radiographs were reviewed and consensus was obtained on the presenting Waldenstrom stages. The severity of disease was rated by Catterall and lateral pillar classifications. The outcome was determined by the Stulberg classification. The right hip was the first affected in 25 of the 33 hips.

Results: These are summarized below.

Conclusions: The present report, with 33 patients, is the second largest series of patients with bilateral LCPD to our knowledge. The second hip involvement was milder than the first, but the improvement in outcome was statistically insignificant.

Between 1986 and 2002, 42 patients with synchronous multifocal osteosarcoma were treated with two different protocols of neoadjuvant chemotherapy. When feasible, the primary and secondary tumours were excised as a combined procedure.

After initial chemotherapy 26 patients were excluded from simultaneous excision of all their secondary bone lesions as their disease was too advanced. In 12 patients only isolated excision of the primary lesion was possible. For 16 patients simultaneous operations were conducted to excise the primary and secondary lesions. This involved two supplementary sites in 15 patients and four additional sites in one patient. Of these, 15 attained remission but 12 relapsed and died (11 within two years). Three patients remained disease-free at five, six and 17 years. The histological response to pre-operative chemotherapy of the primary and secondary lesions was concordant in 13 of the 16 patients who underwent simultaneous operations at more than one site.

The prognosis for synchronous multifocal osteosarcoma remains poor despite combined chemotherapy and surgery. The homogeneous histological responses in a large proportion of the primary and secondary lesions implies that synchronous multifocal osteosarcoma tumours are not multicentric in origin, but probably represent bone-to-bone metastases from a single tumour.

Metachronous multifocal osteosarcoma (MFOS) is a rare form of osteosarcoma manifested by one or more new tumors developing after the initial treatment of primary osteosarcoma. We present a 61 year old Asian male who was referred with 10 week history of pain and discomfort around his left shoulder and low back pain. In 1968, he received radiotherapy followed by disarticulation of left hip for an osteosarcoma of lower end of left femur complicated with pathological fracture. He did not show any clinical features suggestive of recurrence of disease since then until he presented again in February 2005. CT scan of left scapula has revealed extensive osteosarcoma of lower part of scapula, involving subscapularis and infraspinatus muscles. An MRI scan of whole spine has shown evidence of multiple lesions in sacrum, ilium and acetabulum. A core biopsy from scapula has confirmed the histological diagnosis as high grade osteoblastic osteosarcoma. Slides from 1968 were reviewed in the context of recent recurrence and were consistent with features of intermediate grade fibroblastic osteosarcoma. He is currently undergoing chemotherapy prior to planning definitive treatment as there is evidence in the literature that MFOS is a potentially curable condition

Introduction: Patients with malignant spinal disease who have neurologic symptoms are often considered poor surgical candidates. The aim of this paper is to review the effect on neurologic symptoms of surgical management of malignant spinal disease. Methods: A retrospective review of patients treated from January 1993 to June 2003 was undertaken. Pain status was assessed using patient statements and recorded analgesic requirements. Neurologic symptoms were assessed using Frankel’s grading. Results: There were 95 patients (32 females aged 26–83; 63 males aged 15–89). No patients were asymptomatic. 61 of 109 presentations were with multiple symptoms. The most common symptom was pain (99) – either localised (8), non-specific back (56) and/or radicular (57). The next most frequent symptom was weakness (54). The time course of onset varied from acute ward deterioration, with urgent surgery, to slow progression over weeks, prior to elective surgery. 8 cases had sphincteric dysfunction. There were 98 tumours treated. In females, the most common tumours were breast (8) and renal (4) and in males, prostate (13), multiple myeloma (12) and lung (10). The thoracic spine was involved in 62, the lumbar in 18, cervical in 16 and sacral in 2. The vertebral body was involved in 76. There were 109 operations. An instrumented fusion was performed in 82. Surgical approach was anterior in 17 (9 cervical, 8 thoracic) and posterior in 80 (5 cervical, 56 thoracic and 17 lumbar). Six patients had combined approaches (2 cervical, 3 thoracic and 1 lumbar). Two patients were treated for metachronous tumours. One patient had non-contiguous metastases treated separately. One patient was treated for local recurrence. One patient had revision for implant failure (anterior thoracic). One patient was explored after deterioration due to loss of autoregulation. Thoraco-abdominal approaches (12) were associated with ileus (2) and pneumonia (3). Of four cases with deep wound infections, three had received prior local irradiation. Two patients died of pulmonary embolus. 83 patients survived beyond three months. All patients demonstrated improvement in pain status. Thirteen of 29 non-ambulatory cases were able to mobilise postoperatively. There were 32 whose Frankel grades improved. Seventeen of these returned to normal (15 from Grade 4 and 2 from Grade 3). One patient with complete motor and sensory loss improved to useful but subnormal status, three others improved to residual motor function. 11 other patients improved one grade. Of those whose scores did not change (76), 53 remained normal, eight maintained useful but subnormal status, five were stabilised with residual motor function, three kept some sensory perception and two had complete motor and sensory loss. One patient deteriorated from residual motor function to complete motor loss. The outcome for sphincter dysfunction (8) was not clear from the notes. In no case was a specific change in function documented. Discussion: Surgical treatment of malignant spinal tumours is worthwhile. Posterior approaches are versatile and should be considered. Surgery is effective in the management of pain and preserves or may significantly improve neurologic function