Tumor resections from the pelvic girdle often pose daunting reconstruction challenges for orthopaedic surgeons. In the September 2, 2020 issue of The Journal of Bone & Joint Surgery, Ji et al. report early results from a series of 80 bone-tumor patients who underwent pelvic reconstruction using a 3D-printed modular hemipelvic endoprosthesis. The 3D-printed interconnected porous component was generated from an electron beam melting process, and the design allowed for the main iliosacral fixation screws to be oriented parallel to the loading axis of the trunk.
The authors detected no acetabular component instability or implant loosening or migration after a mean follow-up of 32.5 months. The mean acetabular tilt on the reconstructed side immediately after surgery was 46.9o, and it was 47.1o at the most recent follow-up. The mean function score (84%, as measured by the Musculoskeletal Tumor Society 93 tool) was higher than the previously reported range of 55% to 72% from recent studies, and the authors say that the 3-month dislocation rate in this series (2.5%) “seems to be the lowest ever reported.” Moreover, histological analysis of specimens from 2 patients who experienced tumor recurrence revealed bone trabeculae extending toward the implant and bone ingrowth within the porous network.
Still, complications occurred in 16 (20%) of the patients, with wound dehiscence being the most prevalent one. Deep infections, relatively common after pelvic reconstruction surgery, occurred in 5 (6.3%) of the patients, which is a lower deep-infection rate than those reported in previous studies.
Despite the stable fixation and “satisfying early functional and radiographic outcomes” with this 3D-printed modular prosthesis, the authors caution that their short-term results “may prove to be insufficient for the assessment of implant viability.” Nevertheless, any innovation that helps address the many surgical challenges in this population of orthopaedic patients is welcome.
As Sarac et al. note in the latest JBJS fast-tracked article, the phrase “elective procedure” is ambiguous, even though it is supposed to identify procedures that are being postponed to help hospitals cope with the COVID-19 pandemic. Guidelines from the Centers for Disease Control and Prevention (CDC) say that operations for “most cancers” and “highly symptomatic patients” should continue, but that leaves much of the ambiguity unresolved. What constitutes an elective procedure in orthopaedics at this unusual time remains unclear.
To help clarify the situation, the authors summarize guidance issued by states and describe the guidelines currently in use for orthopaedic surgery at their institution, The Ohio State University College of Medicine.
Here are the state-related data collected by Sarac et al., as of March 24, 2020:
- 30 states have published guidance regarding discontinuation of elective procedures; 16 of those states provide a definition of “elective” or offer guidance for determining which procedures should continue to be performed.
- 5 states provide guidelines specifically mentioning orthopaedic surgery; of those, 4 states explicitly permit trauma-related procedures, and 4 states recommend against performing arthroplasty.
- 10 states provide guidelines permitting the continuation of oncological procedures.
In the Buckeye State, the Ohio Hospital Association asked each hospital and surgery center to cancel procedures that do not meet any of the following criteria:
- Threat to a patient’s life if procedure is not performed
- Threat of permanent dysfunction of an extremity or organ system
- Risk of cancer metastasis or progression of staging
- Risk of rapid worsening to severe symptoms
Mindful of those criteria, individual surgical and procedural division directors at the authors’ university developed a list of specific procedures that should continue to be performed. Respective department chairs approved the lists, which were then sent to the hospital chief clinical officer for signoff.
The authors tabulate the orthopaedic procedures that continue to be performed at their institution as of March 25, 2020, but they are quick to add that even this list is not without ambiguity. For example, surgery should continue on “select closed fractures that if left untreated for >30 days may lead to loss of function or permanent disability,” but that requires surgeons to judge, in these uncertain and fluid times, which fractures necessitate fixation in the short term.
Sarac et al. emphasize that such lists, however specific they are today, are likely to change as demands on hospitals shift. They suggest that as the pandemic evolves, a further classification of procedures into 2 time-based categories might be helpful: (1) those that need to be performed within 2 weeks and (2) those that need to be performed within 4 weeks. Sarac et al. also remind orthopaedic surgeons to provide patients waiting for surgery that has been postponed with information regarding safe and effective methods of managing their pain.
Resection of long-bone tumors often leaves large skeletal defects. Since the late 1980s, surgeons have used the “hybrid” Capanna technique—a vascularized fibular graft inlaid in a massive bone allograft—to fill those voids, with good functional outcomes reported. In the November 20, 2019 issue of The Journal of Bone & Joint Surgery, Li et al. report on factors influencing union after the Capanna technique.
The authors radiographically evaluated Capanna-technique reconstructions in 60 patients (10 humeral, 33 femoral, and 17 tibial) and correlated allograft-host union time to the following variables:
- Patient age
- Tumor site
- Adjuvant treatment (e.g., chemotherapy)
- Previous surgical procedures
- Defect length
- Fixation method
- Fibular viability (assessed with a bone scan 10 days after reconstruction)
They also histologically analyzed a retrieved specimen from one patient.
Among these 60 reconstructions, the mean defect length was 16 cm, and the mean time to union of the constructs was 13 months. The overall survival rate of the constructs was 93% at the latest follow-up.
Multivariate linear regression revealed no correlation between allograft-host osseous union time and patient age, defect length, tumor site, or fixation method. Conversely, devitalization of the transplanted fibular graft, chemotherapy administration, and a previous surgical procedure were associated with a prolonged union time. Histologically, the allograft-host cortical junction was united by callus from periosteum of both the host bone and the fibular graft.
Li et al. conclude that “ensuring patent vascular anastomoses of the transplanted fibula is crucial to prevent delayed or nonunion.” They also suggest that Capanna-technique patients who have any of the 3 “adverse factors” noted above should be treated with extended postoperative immobilization and delayed weight-bearing.
JBJS Case Connector debuted digital whole-slide images back in 2016, and the February 27, 2019 case report by Lans et al. put that ability to link to and navigate an entire microscope slide to good use again.
The 27-year-old man described in this case report presented with a progressively painful right forearm. Conventional radiographs and MRI led clinicians to suspect a rare desmoplastic fibroma of the proximal aspect of the radius, but it was not until a CT-guided core biopsy was analyzed histologically that the diagnosis could be confirmed. The histologic findings, depicted in a digital whole-slide image, revealed a fibrous to fibro-osseous lesion composed of fibroblast-like cells with varying degrees of hypercellularity.
The patient subsequently underwent a wide-margin resection that preserved the radial head but created an 8.5-cm defect, which surgeons reconstructed with a vascularized fibular autograft. At the 2-year follow-up, the patient’s QuickDASH score was 2.7 and his PROMIS Upper Extremity and Physical Function Short Form score was 42.
For more information about JBJS Case Connector, watch this video featuring JBJS Editor-in-Chief Dr. Marc Swiontkowski.
Denosumab is an FDA-approved drug for osteoporosis. It works by binding RANKL, thus inhibiting osteoclastic activity. Denosumab has also been shown to have a favorable impact on tumor response in relatively small, short-term studies among patients with giant-cell tumor of bone (GCTB).
In the March 21, 2018 issue of The Journal, Errani et al. report on a longer-term follow up (minimum 24 months, median 85.6 months) in two cohorts of patients with GCTB who were treated with joint-preserving curettage: those treated with curettage plus denosumab and those treated with curettage alone. The study found that denosumab administration was significantly associated with unfavorable outcomes in patients treated with curettage. Specifically, the local GCTB recurrence rate was nearly 4 times higher (60% vs 16%) in patients treated with denosumab plus curettage, compared to those treated with curettage alone.
Recent in vitro studies have shown that denosumab only slows giant-cell multiplication to some degree. The authors point out that patients treated with denosumab in this cohort study had more severe GCTB disease, which would seem to further confirm that cellular proliferation of giant cells is ineffectively slowed by this RANKL-binding drug. What’s most important about the Errani et al. study is that it’s the first one to look at the longer-term outcomes of denosumab usage before and after curettage for GCTB.
The authors emphasize that while their study shows a strong and independent association between denosumab administration and a high level of local recurrence, “causation could not be evaluated.” Still, at a time when clinicians, payers, and patients are critically evaluating every facet of treatment, it seems difficult to recommend the use of denosumab in addition to curettage for GCTB. The data in this study should encourage the musculoskeletal oncology community to continue to investigate other adjunctive treatments to be used with curettage for this disease process.
Marc Swiontkowski, MD